G.G.
When I was reading your post, I immediately thought, she's found out what "feels good." It really sounds to me like she's discovered the spot. My son started doing these things at a VERY young age too. Maybe 13 months?? I know a lot of other moms who's baby girls and boys have done the same thing. At first I wasn't sure what he was doing but as he got older, it became more obvious (although, I suspected it from the get go). At 4, he still does it but not very often. We now explain that it is okay but he needs to go to his room in private. They do not understand that it is sexual, only that it feels good. No different than scratching an itch. If this is what she is doing, please do not feel embarrassed. It's a hard thing to see because we adults can't get passed this being "sexual." It is also very common for young children to do this. Do not think you are alone.