Jangan risau, setiap baby develop at their own pace! A few of my mum friends juga ada babies yang took longer to sit independently tapi very early crawlers atau climbers, macam your little one jugak. Kalau he's already climbing sofa, that shows good motor skills, sometimes babies skip the sitting phase and go straight to crawling and climbing! Best to mention it to your paediatrician at the next check-up just for peace of mind, tapi honestly banyak babies yang duduk properly after 9-10 months je.