Do not worry! This is normal. Do not show annoyance or any other emotion if your child knows that she has been caught. "Say something like 'why would you bother - there are other more interesting things to do"? "you'll grow out of it' Dismiss it with laughter - expressing the emotion of why would you bother and no other display or view. However, be aware that in some instances this may evolve usual with children she knows well and with children she gets an opportunity to do things such as sleep over and share beds to sexual touching - however, generally that is at an older stage past ten years. Again the response is 'why would you bother'. Some researchers say that this type of behaviour is stronlgy based between same sexes - they do not know why. Remeber, at all times - to dismiss it as nothing - any other emotion will be picked up on. It DOES not mean your child will engage in early sexual intercourse - or become a wayward girl at 12 - that depends on the parenting that ocurrs between then and now. All this is - really it is exploring the world - as a doctor friend of mine commented when his son went on a similar journey 'just disovered they've got one'
Good Luck