I put G on his back on the floor and he went from a nearly-crawling position to his first independent sit! He just started to be able to sit without support for about 30 seconds earlier this week, and now he thinks he's a big grown-up baby that not only doesn't need support... but doesn't need help to get into the position at all!
It's not good to compare, but Ella was 8/9 months old and pulling-to-stand when she had her first independent sit... which is totally normal.
My babies are growing too fast! Wahhh!