Congratulations! You’re halfway through your child’s first year. No doubt, watching your baby grow to a happy 6-month-old is fulfilling. At six months, expect a lot of new developments, like babbling, solid feeding, and sitting up. This guide shows what to expect from your 6 months old baby. At six months, your baby’s growth will still be slow. On average, your child will gain more than twice its birth weight. This age also signifies many notable developmental milestones for your baby.