I think you did well to know right from wrong, and should give yourself a pat on the back.

Some children though mimick what is dished out to them, ie., a alcoholic parent, a drug addicted parent, numerous uncles or aunties, filthy living conditions, beatings, domestic abuse etc., some children think it is the ''norm'' for instance a 9 year old being the adult, sorting out letters from authorities, phoning on parents behalf, sorting out the shopping, picking Mom up from the floor in a coma state and putting her to bed, doing thier own cooking from the age of 4, looking after siblings, sorting them out for school, and growing up to thinking that this is the normal thing. Unfortunately then doing the same to thier kids and repeating what thier parents showed them. (that is actual fact from a child I dealt with)

For instance Patrick grew up with a Alcoholic father, he watched him beat the Mom to a pult for a miserable £2, he and his 7 siblings sat in a bedroom all day with 4 pieces of bread, all sharing two beds between them, he saw his father come home with different woman....drunks like himself....but the rage and anger over his Mom trying to get the woman/women out spilt over to the kids being dragged around like rag dolls.
As the kids grew up Patrick swore that he would only drink a couple of shandies a time if out with the lads and never lay a hand on his kids or partner, which he stuck too. Two of his other brothers drank like fish and battered thier kids and wives. The other brother almost had a mental breakdown, the girls two came out of it fairly good and have made a success of thier lives, the other is a man hater. Everyone deals with things differently, some of us, like yourself, realise that what happened is wrong, others feel thats the way life should be, other try to stay away in the shadows of life and become shy and some become load and extrovert.
I think it has to be remember the girl is but a child herself still, so I for one hope that she can get sorted and educated. I am sure in time we will hear more about the ''case history'' of the family my only hope is that the baby is safe and the cycle is broken with her.

Kids will be kids. When I did works experience for just one month in a RECEPTION CLASS (5 year olds) I twice caught 2 separate boy/girl pairs looking/showing each other's bits in the house corner and this was a good CoE school!

I was going to write exactly the same a few days ago. This also happened at the nursery I worked at (although it was the same girl instigating it everytime).
Must happen all the time, although its shocking to see at that age!

I think most kids go through the "if you let me look at yours i'll let you look at mine" thing tbh. I remember playing doctors and nurses when i was younger, nothing sinister - its just innocent curiosity at the differences between sexes i think at that age. I turned out ok !

YES most kids do - but i think when their is a constant instigator then some questions need to be asked......