The Other Mothers by Katherine Faulkner

 Tash (Natasha) and Tom are happily married Londoners, with a young son named Finn. Tom is an ER doc and Tash is a reporter, who is now working freelance. When she takes Finn to his new daycare, he gets hysterical and doesn't want to stay. The director suggests she make friends with some of the other mothers and set up some play dates. So she starts hanging out with 3 of the mothers--who are all much wealthier than she is. And soon she is kind of swept up into their world and corrupted by their influence--getting a secret credit card to cover the expenses of the new clothes, spa days, and expensive brunches that she and Tom can't really afford. At the same time, she is investigating the death of a nanny that was ruled accidental but she has her doubts. She is shocked to discover the dead girl was the nanny for one of her new friends. The more she investigates, the more she wonders whom she can really trust. Can she figure out what happened to Sophie the nanny? Will her marriage survive her friendships with "the other mothers"? And who keeps sending her threatening messages to stop looking into Sophie's death?

This book really does not make these wealthy mothers look too good. And you feel bad for Tom, an overworked good guy who has no idea what his wife has gotten into. It had an interesting ending that makes one think about the choices people make.