The Messy Lives of Book People by Phaedra Patrick

 Liv married Jake when they were both very young. Now they have 2 college-age sons. He works for his family's book-binding company and she is a house cleaner. Her newest client is successful writer, Essie Starling. Essie is a handful but she takes a liking to Liv, who always wanted to be a writer. As she gets drawn more and more into Essie's world, Liv can see her world beginning a new trajectory.

I don't want to spoil the plot twists, so I won't give away too much of the story. But Liv is a likeable heroine trying to figure out what she really wants to do with her life.