Fair Peril — Nancy Springer

The art of storytelling and the power of a mother's love imbue this feminist fantasy novel -- a contemporary riff on the tale of the frog prince  

Once upon a time there was a middle-aged woman whose husband dumped her the month after their twentieth anniversary . . .
 
Divorced, overweight Buffy Murphy is not a happy camper. One April afternoon, she walks into the woods . . . and meets a talking bullfrog. He asks her to kiss him so he can transform back into his princely self. This being modern-day Pennsylvania, Buffy figures she's better off with a talking amphibian than a cheating husband, so she takes him home. The fun really starts when her rebellious teenage daughter, Emily, kisses him.
 
Suddenly, Emily and her handsome prince have vanished into the land of Fair Peril, an enchanted realm that can only be accessed through a portal in the local mall. Aided by a gay librarian named LeeVon and hindered by her fairy-godmother-in-law, Fay, Buffy shuttles back and forth between the real world and Fair Peril. Does Emily really want to be rescued, or does she just need someone to love her? It's up to Buffy to figure out the key to reclaiming her daughter -- and maybe herself, as well.