How long do babys go thru withdrawal?

The Emom is my cousin's daughter. I think it's called 1st cousin once removed. It will be an open adoption, and I'm hoping this program will work for her and she'll have a different lifestyle than the one she has been in. If she stays in our hometown after birth, we are likely to have lots of contact. If she goes back to her hometown, not so much. I sure hope baby is thru detoxing by the time it is born. It must be heartbreaking to watch!