To: My little cousin is a beautiful little 12 year old tiny redhead who all the guys have a crush on.
Me: Pregnancy is a very likely result in one so young and fertile.
There is not much you can do, except go with her to her parents and tell them, together, what happened and what you think the outcome is likely to be.
How you together deal with whatever happens next, is about all you can hope for.
Good Luck