personally i feel that you should go to her school and her daycare and find out what is going on. If you know for a fact that it is not coming from your home, and she only goes to school and daycare. Then you go there and you talk to principal, teacher, or whomever else. Someone is putting these things in her mind. It may be that she has gotten something from tv. These days it is almost impossible for our children not to come in contact with sex. It is everywhere and I hate it. Heck hardees even is part of this stuff now. Get the teachers involved so they can watch better what is going on in case another child is doing these things. You must put a stop to it before someone thinks something strange is going on in your home, and calls someone about it. Please talk to her teacher so she can watch out for anything going on at school.
i cant see how a 6 yr old could even come up with sexual discussion or play if she hasnt seen it or heard it somewhere. we arent just born with knowing this. either she has seen a movie or you and your partner without you knowing, or an older child has said something. probably the last one. my son is 9 and will be starting the 4th grade. you would be surprised to hear the other kids say! if she is learning this at school on the playground i dont know what to tell you. you could have a meeting but really what would that do? if you become angry or upset with her it might make it seem more fun to keep it up. but if you ask her to stop discussing this and she keeps it up with the younger kids i suppose you have to discipline in some way. maybe you could explain it to her that she is doing very grown up things and you dont want her to do this anymore. i think at this age its pretty common to be interested in body parts to a point. with me and my son ive never hid the facts i have a different type of body. i also made it clear he is welcome to ask questions and we can discuss it (within his age limits). i wish i could help you more, but from other children i have seen its not uncommon.