Venting/need advice

A little while back my niece posted on Facebook about a "friend" that was 19 and pregnant with her second child and was considering abortion because the father (not the father of the 1st child) didn't want to have the kid. She was also questioning why a man would have sex with a woman and then not want them. So she and I were talking and I let her know that if her friend needed someone to talk to she could always give her my # because I know it's not always easy to talk to your mom or even you own aunt without the judgement. Technically, my niece is my sister's step-daughter. We come from a blended family but don't use the words "step" or "half". We are the only real family that she has. My sister is "mom" and she calls her biomom by her 1st name as hasn't actually mothered her in about 12 years. One day I get a call from my sister and she tells me that she thinks her daughter had an abortion. Said she knew she was pregnant because she called for advice but hasn't heard from her in a while. Imagine my surprise when i heard this because all this time she sold the story to me as her friend when the whole it was her. In talking more to my sister she tells me that she told me niece to call me because 1, I live closer than my sister does and we can have face to face conversation 2, because my niece is actually hesitant about abortion but knows she can't parent. It's also not a secret in my family that my husband and I have had a difficult journey becoming parents. After 2 years of trying I finally got pregnant in August 2010 but unfortunately miscarried twins. Moving on...I got an email from my niece about my husband I taking custody of her baby girl due in August 2011 and then moving onto adoption. Of course that made me happy because not only would my niece not be having abortion, the child would then remain in tact with our family. Since then though, no one can get her to talk about it. I'm sure this is a very difficult decision for her. She tells my sister all that time that she knows she can't raise this baby because her life is in a shambles right now, she already has no support from the current child's father (he's not even 2 yet) and doesn't want to bring a second child into an unstable situation.She also wants to make sure the baby knows who she is (my husband and I are both okay with that). I give her kudos for coming to that decision. But then at the same time, this child is due in 4 months and time is running out. I don't want to push her. I don't want to push her away or make her close up because at this point she does talk to my sister about it. I don't know should my hopes be up/down? My fear is that one day I'll get a call saying "Auntie, I'm in labor are you coming to get the baby?" and I'll have to stop at Target to buy baby stuff on my way to the hospital. I guess I just want to be prepared. I'd also like for us to sit down and talk a lawyer and for my niece to have proper counseling. I also know (via Facebook) that she's still partying, drinking and smoking weed. And that her son is constantly in the care of her "friends". At this point I fear for him too. I kind of feel like it's just a matter of time until someone calls CPS. UGH! This is so frustrating. What are your thoughts? How should I proceed? Thanks in advance