All I can tell you is that you have to deal with it indirectly or it will get worse. So you have to pay attention to when she is most likely to do it and try to beat her to the punch and engage her in another activity. Kids always explore when they are bored and obviously don't differentiate for propriety. But it's important that even emotionally, you stay calm because she will sense your anxiety about it and do it more just to see when you will break... and not because she's malicious but because she's curious about what makes mommy tick and why. And if you talk to her about it directly, you can use "I" or "mommy" statements. Such as "Mommy doesn't touch herself there right? Let's play with Water!" However, you are right that it is normal especially at her age and her self discovery is important so I wouldn't pursue it too much. She will get past it and observe/imitate that no one else touches themselves like that so she will catch on. Good luck, N