Mary Ann, to say the least, is obsessed with cleanliness. She will often spend hours washing her clothes (as is revealed in the comic book); just the slightest mess on her clothes causes her to react quite violently (either physically, verbally or both). She shows great concern for the White Rabbit's well-being (referring to him as "Master Rabbit"). Despite having dreams of being a princess (like most girls her age), she states that "all she really wants is to be [herself]".
Though she wasn't seen in the film, she was the main protagonist of the comic series.
During Chapter One: "Impostor!", she is first seen walking along a pathway, worrying that she'll be late due to her overly-sized obsession with cleanliness (as is pointed out by her sentient feather duster, who is aptly named Feather). Taking a bizarre pathway (hoping it is a shortcut), she ends up at her intended destination - the White Rabbit's home.
Greeting her master (and receiving a lecture from him due to her being late, as well as the news that Alice was pretending to be an impostor of her), she hands the Rabbit his gloves and reminds him that he has three minutes to get to the Queen's castle; however, worried as the White Rabbit may be, things grow worse when the Cheshire Cat appears and tells them that the Queen is coming to the Rabbit's home now, believing him to be a traitor to her rule after having heard a tall tale from Tweedle Dee and Tweedle Dum about how the White Rabbit was plotting against the Queen with the help of Alice. Before the Rabbit can do anything, the Queen arrives.
Though the Rabbit claims innocence, a stray hair of Alice's found laying on the floor doesn't exactly put him in a good position. Soon enough, a pastry lands on Mary Ann's uniform (courtesy of the Queen) and, in an act of rage, she attacks the Queen and knocks her out with the scepter of the long-missing Queen of Spades (which was given to her by the Cat). Before the Queen can capture her and the White Rabbit, the both of them have fled into the Tulgey Wood, concluding the chapter.
Later, in Chapter Two: "The Tulgey Wood and the Treacle Well", she is first seen dusting off a mushroom for the White Rabbit to sit upon. While her employer laments how poorly things have turned out for him, Mary Ann fears that she'll be dead much sooner than the White Rabbit. However, the Rabbit claims that she is safe because of her position as a servant (despite her having knocked the Queen of Hearts out cold). Just then, he gets an idea- he could hide at Mary Ann's home until this madness brushes over (since he figures that even he doesn't know where Mary Ann lives, so neither will the Queen).
However, Mary Ann has her doubts, since her home is less than pleasant: it's a one-room shack (which is kept extremely tidy), it's surrounded by slowsand (a substance that, unlike quicksand, which sucks people down into it, slows people down) that can only be crossed by hopping on the backs of turtles and there's a massive rock that is teetering on the very edge of an overhang, forcing everyone to be quiet, lest any noise causes the rock to tilt off its perch and crush the house.
Suddenly, the group overhears caterwauling coming from nearby. Sure enough, the Cheshire Cat is causing trouble again; however, Mary Ann insists that the Cat stop, as reciting "Twas Brillig" in the Tulgey Wood is bad luck. Naturally, the White Rabbit doesn't believe it and, after the Cat gets him all worked up over his intellect, he recites most of the poem (the first four stanzas) and attracts the vicious Jabberwock. While the beast chases the Rabbit, Mary Ann runs away in fear. After she stops running, she realizes that the Rabbit is still in trouble and feels that she should help him; however, Feather says that Mary Ann should look for someone or something better. Mary Ann, on the other hand, feels that she can't just abandon the White Rabbit. Just then, Mary Ann notices a well; sadly, it turns out to be a treacle well. Despite this, Mary Ann hears what sounds like voices coming from within it.
She leans too far in and falls before, in a method clearly inspired by Alice's entrance into Wonderland, her dress acts as a parachute. This only lasts for a few seconds, as Mary Ann's dress loses stability and, after sustaining some bonks to the head and injuries to the back, she lands at the bottom of the well in a filthy treacle mess. Unexpectedly, she meets a trio of green-skinned ghouls known as The Sisters- Tillie, Elsie and Lacie- and two mysterious figures referred to as "Sir" and "Madame" at the bottom of the well. The chapter concludes with Mary Ann handing the Queen of Spades' scepter to "Madame".
Mary Ann isn't seen again until midway into Chapter Three: "You're My Maid Now!", where "Madame" is revealed to be the Queen of Spades and "Sir" is revealed to be the King of Spades. Mary Ann introduces herself, but flips out and swears profusely when The Sisters try to "clean" her up. The Queen calms her down and, believing that Mary Ann is her new handmaid now, gives her some new rules to live by (which, when compared to the rules given to Alice by the Queen of Hearts when they first met, are the exact opposite) and simultaneously cleans her by placing a bar of soap in her mouth. Despite Mary Ann's chance at a new job, Feather warns her to be careful, as he suspects that the Queen of Spades is trying to enslave her mentally. While the two acquaintances argue, who should arrive but the Caterpillar, who utters that one can change their position in life by "nibbling on the 'correct side' of a mushroom". Afterwards, Mary Ann laments what might have become of the Rabbit.
Soon, Mary Ann notes the King of Spades is seemingly nonresponsive; the Queen of Spades assures her young friend, however, that she is control of both hers and her husband's thoughts, dreams, opinion and voice. After learning this, Mary Ann walks away to try and figure out an escape from the well; as she thinks things over, the White Rabbit ends up landing on her back. After cleaning herself again, Mary Ann asks the Queen if there is another way out of the well; sadly, the Queen states there is no way. However, in an absent-minded bit of cleaning, Mary Ann dusts off the shrinking scales of the Caterpillar and shrinks everyone (save the Sisters) down small enough to ride the Caterpillar out of the well; though the Caterpillar refuses at first, a quick angry comment from the Queen sets him straight, as the Queen and her entourage leave the well (and the Sisters) behind.
Mary Ann and her acquaintances are next seen in Chapter Four: "The Curious", when the shrinking scales' properties finally wear off. The group find themselves in the company of the Mad Hatter, the March Hare and the Dormouse, all of whom happily welcome the group to their never-ending tea party (though the March Hare notes that the return of the Queen of Spades is sure to attract some attention). The White Rabbit has Mary Ann sit next to him during the party so that she may learn proper tea party etiquette; however, the fact that every last dish and piece of silverware is filthy (not to mention the fact that the Dormouse is living in a teapot) has Mary Ann more than distracted.
Deciding that something must be done, Mary Ann gathers up every last dish that isn't being used, she begins to clean them up, but literally goes out of control and enters a cleaning frenzy that is so furious that the patterns on the fine china dishes end up removed entirely! The March Hare's attempt to restore the china only worsens things, as nearly everyone ends up thoroughly drenched in dirty water; naturally, the Queen of Spades can't stand this and orders that the group head to the home of Sir Edward, a famous tailor in Wonderland, so that they might gain some better clothes. While the Queen and King (who suddenly stands up for himself in only this one occasion) have a fight, the Mad Hatter and the March Hare relate Alice's visit to their party to the White Rabbit and Mary Ann. The Hare relates that Alice has been seen in Looking Glass House and that she has a cult following- a group referred to as "The Curious" -who have holed themselves up in Looking Glass House. The fact that Alice has a cult following proves to be shocking and disturbing to Mary Ann, who feels that Alice is terrible (in contrast to Feather, who seems to enjoy Alice more and more as time goes on).
After some more discussion, Mary Ann follows the others to Sir Edward's home/tailor shop. Mary Ann is the first person to receive some new clothes (thanks to Sir Edward's quick work and the aid of his "porcupin" pet). Though Mary Ann doesn't approve of how Sir Edward hemmed her in (claiming that he despises "loose ends"), she does find him somewhat charming. As Sir Edward puts the finishing touches on Mary Ann's outfit, he asks Mary Ann if her new job as a handmaid is a step up in the world or not. As Mary Ann remains neutral about how she feels, she (after suggesting a cure for Sir Edward's moth problem) suggests becoming a possible aid in the event that working for the Queen of Spades becomes undesirable; however, the Queen overhears this and sends Mary Ann "out for some fresh air".
While taking in the scenery, Mary Ann and Feather discover Looking Glass House and spy a pair of "The Curious" entering the house after uttering a secret pass code. Thankfully, the two leave the door open and (after Feather carelessly rushes in) Mary Ann decides to see what all the fuss is about. Entering the decrepit manor, Mary Ann finds all of "The Curious" ogling a dusty mirror surrounded by candles. Dusting off the dust, Mary Ann sees Alice's face at last and recalls (just as the chapter ends) that she had dreamt about Alice.
Chapter Five: "The Dusty Dunes" opens up with Mary Ann recounting the dream she had of Alice- how she felt like she was walking about in Alice's body and saw things as Alice did (suggesting, perhaps, that Alice and Mary Ann are two halfs of a whole being).
- Though this is never clearly stated by the comic book, it is believed that Mary Ann is something akin to the Wonderland version of Alice. As two beings cannot exist in the same world at the same time, Alice caused Mary Ann to disappear while she went through Wonderland and the opposite also occurred for Mary Ann.