Concerns about my DD's friends

[67mummy]

My DD is 15 (year10) and her cousin attends the same school. Her cousin is more shy, reserved and get your head down to work type of girl but DD is the complete opposite. Obviously like most schools you've got the 'popular' girls and boys and all the pupils know who they are and not to mess with them. My niece has repeatedly told me that my DD is friends with them and is really cocky, self centred and gang up on the more vulnerable children of the school (e.g. my niece and her friends) but they are completely fine with each other when with family.
My niece has said repeatedly that she has been out for a drink and had sex but I'm not sure if I should believe her or not. I have asked my DD multiple times about going and doing things she shouldn't be but she denies it every time. Niece has told me that in lessons they talk about the amount of times they've done things with lads how many lads they've been with and who they're wanting to date and is telling me she says things about having sex e.t.c.
I'm not sure what to do so just need a bit of advice/help.

p.s. niece and DD are the same age and in most of the same lessons at school

What would DN gain form this?

Does your DD need taking down a peg or two? She sounds vile.

Of course your dd is going to deny it.

Does your niece have anything to gain from lying?

Is your dd often out / away and unsupervised and as such have opportunity to do these things?

I was going to post on a similar matter, except it's one of DD's friends who talks like this and has a "reputation" at school.

DD (14) says that most of the rumours and things this girl says about boys and sex are made-up. I have no idea, of course, but it's not great if your DD is saying things like this (even if it's complete fantasy) because people will believe it.

Perhaps you should have a chat with your DD about how in just a few years, relationships and drinking will be normal among her age group and there's no point making stuff up now.

I remember when I was at school girls (including me) making up all sorts of stories about things they'd done - when they hadn't done anything or not much.

I know, we all wanted to be more experienced than we really were!

I blush now when I think of some of the things I said I'd done (from age 12!), but others were the same. I remember there were a couple of books I read that gave me ideas. They belonged to the two older sisters of a girl I was at school with and she brought them in. I was glued to them! Very informative indeed.