Am I the only one who doesn't see anything wrong?
She's having fun and having a bit of dance with people who might be on the pull themselves, yes, but what's to say these numbers she's taking aren't people she just wants to be friends with?
This comment, "So she can make new 'friends'.
We're both in 2nd year so its not like she's off at a brand new uni trying to make brand new mates in fresher week. She already has a tonne of friends from last year.", really bothers me.
So what, is she only allowed to make new friends and contacts in the first couple of weeks of the first year? She will meet new people all the time throughout her uni career, and throughout her life. You seem to have trouble dealing with this right now.
If there was anything suggesting that she's even considering taking any of this further than a dance, a friendly drink, and perhaps new friend/contact, then yes, worry. But from what you've posted, she doesn't seem to be to me.
I will admit that a tiny percentage of the men probably want to be just friends. But I think she deserves the benefit of the doubt.