Hello and Welcome.
I understand your concerns. I would say that she is trying to kick some very very hard drugs. Maybe the best thing to do would be to back off and give her (and you) some space. You are going to have to see how she handles this for herself and if she has the ability to work a program and stay clean. Time tells all things.
I know that is not the magic answer you want, but it is a true one. In the mean time, go to meetings and get support for you and your little one! Congrats on the baby and for taking the initiative to do the right thing by your child. They have to be #1!
Good Luck and God Bless!