I would say 3 to 4 hours is good, I think the important thing is that she is eating regularly. But as far as the other stuff, I agree with the other ladies, get the help you are entitled to from the agency.
Adopt, I agree with Margy. Why don't you have professional medical newborn help, from the adoption agency, so you know what sleep intervals are normal for newborns, and particularly this newborn? It's incredible that you are coming to an internet forum for answers that should have been explained to you, and you should have a 24 hour emergency number to call for additional questions. I'd say call the hospital that adopted your baby out, or if you don't know that, the adoption agency for these questions.
Best wishes.
I believe you need some expert advice here I would only be guessing definatly get the sweet child some more help, You know sleeping 3-4 between meals sounds okay if she sleeps well, I would say withdrawal was a small part of it ,however as I say you will get more advice from a proffesional .Good Luck this baby is happy to have a caring Mom ...