A: Dear Thumbs, The best way to address this is directly, as uncomfortable as it may be, because it is that important. Next time you see her, say something like: "I'm so sorry for asking, but I just can't shake something my daughter said. She thought you might be using your phone while driving. She may have been wrong, but if you did, please promise you won't anymore. You are carrying precious cargo." She may deny it, but she'll get the message how important this is to you—and that your child is watching. If sticking up for your kid's safety puts a strain on your relationship with her, so be it. You can find another arrangement for your daughter.