Kaiden first sat up alone at 13 weeks, my MIL didnt believe me so i took some pics of him, hes gradually been able to sit up for longer, he can walk too since 19wks if you hold his hands, but hes done alot quite early i suppose all babys are different, my neice cara is almost 8 months and she sat up for the 1st time the other day, and she wont attempt to stand at all, as yet, funny how they are so different XKelX