L.V.
This is the first time that I have responded to an inquiry. I felt 'compelled' to tell you that I really don't think you have anything to worry about. The 'parts' are just parts - in the right place, like she has probably seen on mommy and daddy.
Try dealing with this one....
The other day, I walk in on my 18 month old baby girl and her 4yr old brother playing in the family room. She has this BIG wad of toilet paper stuffed in the front of her shirt. I ask my son, "What is THIS???", he (without looking up from his Bob-The-Builder set) calmly says, "I put paper in her shirt to make her look like a REAL woman." (???!!!)
I didn't know whether to laugh or vomit....so I just walked back out of the room..... ;)