When I had my daughter they had to taper her off of Methadone. Sneezing is a sign of withdrawals, also bad sleep patterns, eating problems, seizures, low birth weight, dirrhea, vomiting, tremors, high pitched cry, and nasel congestion. There is alot more signs. You can look up signs for NAS online. I would consult the doctor that is caring for your baby. They should be able to tell you if it is withdrawals or just the cold. Good Luck and I hope your baby feels better soon.
Methadone detox is a lot like a cold, with diarrhea. Runny nose, cranky, chills, the whole bit. She may just be in withdrawal. Subutex does the same thing, though a little different. Are you off the subs now?