Someone started sitting up!
The first time, I sat her up just to see if she could do it and lo and behold, she could!! She was totally freaked out though. Her eyes got huge (well, more huge than usual) and she the look she gave me said, "What the heck just happened here?!" And then she tipped over backwards which made her cry.
She wasn't real keen on sitting after the head bonk, but after a little practice she seems to have mastered simultaneous sitting and playing.
(Thank you Nana, for the fun ribbon pillow!)