My experience is generally that if the pregnant girl is being that difficult and dysfunctional, it doesn't augur well for the baby's future.
Frankly, adoption would probably be the best thing in this case. Loads of suitable Irish couples travel abroad for adoptions at great expense - maybe €30,000 for one adoption. Adoption is almost certain to give that baby a greater chance in life.
Unfortunately, we have gone from a situation in Ireland where most unmarried women gave their baby up for adoption to an equally ridiculous situation in which it is socially taboo to give one's baby up for adoption, no matter how dysfunctional the mother and father of that baby.
You will come under huge pressure to help out so that your daughter can keep the baby.
Are you willing to stand your ground if you feel that this is not the right course of action?
The girl is 15 and has just found out she is pregnant....totally to be expected she would have an "attitude", god love her she is probably terrified about it all.
Adoption can be wonderful but you can't advise on the basis of a few posts. Something like that is a big decision that should only be made after lots of counselling.
Its not the OP's choice, she can guide, advise etc but at the end of the day the mother of the baby has to be the one to make that decision. Pressure to put a child up for adoption is as bad as pressure to abort.