A job that is demanding more of her time each and every day has Tracy worried about how to best care for Danny. As a result, when a concerned day care center employee offers to be a fulltime nanny, Tracy gladly agrees. But while Celia assumes that Mona is a simple domestic eager to do whatever she's asked, it soon becomes clear that she's sorely mistaken. Meanwhile, Charlotte and Dr. Bryan find it harder than they thought to resurrect their failed relationship. Despite Celia's warnings about keeping Mona in her place, Tracy gives the new nanny more and more responsibility. As a result, she begins to see Danny becoming more comfortable with Mona than he is with her. Meanwhile, Tracy finds herself caught in the middle of the ongoing battle between Charlotte and Doug. Though warned to put aside her anger over the growing bond between Danny and his nanny, Tracy can't help but feel bad after her son's first word sounds just like "Mona." But her worst fears are confirmed after seeing him ...