Sister in law 20 week and into heavy drug use

My husbands sister is around 20 weeks (from what I have counted, she has no idea) she is a heavy drug user and shoots heroin, smokes, takes pills recreationally when she can't get her fix off of heroin and refuses to take her prenatal a because they make her "sick" my husband has reported her to the police yet they always end up letting her go (he believes she is working for them) it breaks my heart everyday to see her growing belly, I don't know what to do she is in complete denial showing me pictures for her baby shower and nursery ideas. We have tried everything aside from locking her in our basement. I don't know what to do ): she stays with his mother and don't think she has ever spoken more than 10 words to me until recently wanting to bond as girls since she has no one to talk about her baby with. I have told her there is no way on earth she will be able to keep her baby, but she stays in denial and continues to shoot up. She hasn't been to a doctor because she can't let them see her track marks. Is there anything we can do to save out niece or nephew if she is working for the police!? **Also to add my husband has tried to pay for her rehab for about two years and she has no desire to quit