Lahwhinie

Queen Lahwhinie (often misspelled as Lahwinnie, Lahwinie, and numerous of other name variations) is a mouse living somewhere on Hawaii. She has a strong physical resemblance to Gadget Hackwrench, differing in fashion style.

Personality
She has been chosen to become the queen of the mouse tribes she lives with because she is adored by them, due to her ability to cease the imminent eruption of a nearby man-made model volcano. In reality, she simply discovered the mechanical functionality and used it to gain power of her tribe. To become a queen, she had to undergo a series of dangerous tests. After she met Gadget, she swaped roles with her and let Gadget undergo the series of tests. Meanwhile, Lahwhinie pretended to be Gadget. Nevertheless, at the end she became the queen of the tribe of mice.

Relation to Gadget
It's often been discussed if Lahwhinie and Gadget are sisters because of Lahwhinie making at one point in the episode, about her and Gadget being "like sisters." That could never been fully discovered and so it's still a well kept secret.