Baby will be 6 months old in coming week, she has rolled from back to tummy few times but mostly likes playing on back.when she is on tummy time her head is stable but when I try to make her sit with support her head feels wobbly sometimes when carrying in upright position also .She has not yet rolled from tummy to back.She also has developed flat head staying on back. My baby was born at 36 weeks 4 days, there was no issues but I had history of miscarriage so on doctors suggestion we did c sec .She also cried immediately after birth. Is there delay in milestone development, she is very active , playful and gaining weight,smiles and kind of recognises her name .