I think this may have been asked before but maybe in a slightly different way.....
This sitting unsupported as sign of readiness to wean - well DS (5 and a half months) can sit up if you plonk him on the floor quite carefully and prop him up with his arms.
But then after a few seconds he usually sees something he wants, leans for it and falls over.
Does this count as sitting unsupported? If not, what does?