Hmm it's hard to say if my gut is telling me anything, she seems fine every other way, claps her hands, waves goodbye, babbles and yells if she wants something. She is smaller than the others though, quite the skinny little chicken! So to me she "feels" like she is only 7 or 8 months old, but who knows if that's just cos she's my last so I don't want her to grow up too quickly lol