Princess Astrid

She is hildegard's big sister who appeared in the flash back when hildegard was singing the song know it all and from the sofia the first season 2 episode the princess stays in the picture.

Story
while hildegard was singing about her bad first day at royal prep when she was young, she saw her big sister in the sun so she ran up to her and friends to be with them, they were doing the twirls and asked her to give it a try but when hildegard did, she fell down and her sister's friends laughed at her but not her because she felt bad for her younger sister.