The Younger Sister - Catherine Anne Hubback

Emma Watson, the youngest child of six from a poor family, was sent away as a child to be raised by her wealthy aunt and uncle. When her uncle dies and her aunt remarries, Emma (now a pretty, well-educated, and opinionated young woman) returns home to help care for her ailing father and reconnect with her estranged siblings. She quickly must learn how to behave among the less affluent and navigate her way through the affections of many young men vying for her attention.

The Younger Sister is the first published completion of Jane Austen's unfinished novel The Watsons. (Summary by Mary Kay)