Asking to see other kids privates

We are very good friends with my neighbors and their kids.  But their 6 year old daughter has now asked of 4 different occassions to see my kids (boy 5, girl 3) and the neighbor boys (same ages as mine) privates.  I feel that she knows that it is wrong but keeps on doing it.  No touching has occurred.  I am concerned at this point because the last time that it happened she purposly took the kids to a private place where no one else could see.  I spoke to her mother about it and she at first was just very defensive then said the she is not surprised because her daughter see's the boys peeing outside.  Is it normal for her to continue to ask to see and even secluding them?

[Kevin Kennedy, Ph.D.]

No, this is not normal behavior in this sense - one should not expect to see such behavior in a six-year-old. It is also of concern that she even has the opportunity to be outside of supervision with anyone her age, let alone younger.