Firefly Lane is the third Kristin Hannah book that I've read, and although I didn't like it quite as much as True Colors, it was a close second. I really enjoy her books — she writes dynamic female characters, with compelling stories.
This novel follows the lives of two friends, from childhood into adulthood. Their lives diverge when one of them chooses her career over family and relationships, and the other chooses family. Their friendship is fiercely devoted yet extremely rocky, as each seems to have a difficult time understanding the other's decisions.
Firefly Lane reminds me a lot of a wonderful novel I read a long time ago, Summer Sisters by Judy Blume (one of her adult novels). I highly recommend this novel — I loved it so much I could hardly put it down until I'd finished!