Q. Stopping Former Nanny From Sleeping With Other Dads: My children attended a wonderful preschool until they turned 5. When our youngest child left the preschool my husband and I hired their favorite caretaker, twentysomething Kate, to be their part-time nanny. Over the past three years, Kate has practically become part of our family. Last year, I wrote her a recommendation that helped her gain entry into a prestigious special-education college program. Last week, I found out Kate and my husband have been carrying on an affair for two years. I don't know yet if my marriage will be salvageable, but Kate is no longer working for us. I know Kate wants to continue to work as a child care provider. I think that if most moms and facilities knew about her past, they wouldn't give her the time of day. I'm also worried she'll betray other families the way she betrayed mine. I'm not sure how to make sure she doesn't work in a child care setting without going down a seriously psychotic path, like mass-emailing every day care in our city. Should I do my best to forget about Kate? Or is there a sane and justified way I can keep her from hurting other families?