DEAR MAYO CLINIC: I have two children—a 3-year-old son and a newborn daughter. My son is beginning to notice his anatomy more, touching his genitals and asking questions about his sister. He is noticing that her anatomy is different from his. He also asked how she got into and out of my body. I am wondering if you have advice on how best to answer his questions and address other curiosities that might arise as a result?