M.S.
I had this same problem with my daughter. I swear I held her for the first 6 months because she screamed any time we put her down, so she was delayed with both sitting and rolling over. Her pediatrician referred her to Early Intervention and they gave us a lot of help and encouragement. My daughter is now 18 months old and -- knock wood -- she is running around with the best of them! Early Intervention is a free service by the state -- or at least I know evaluation is free. Treatment or whatever other follow-up might have a small fee. I think they ended up billing my health insurance for part of it but we never paid a dime. As far as how to say something to your friend, that's a really tough one. I guess it depends on whether she's concerned about the baby reaching her milestones or not. Maybe I'd wait until she brings it up and then ask her what the pediatrician has to say about it or whether she's heard of early intervention. Depending on how close you are to your friend and how much you want to become involved, you might even contact your local Early Intervention office for tips. Good luck!