Hi,
I think sometimes it's better to have a curious and active child rather than a listless kid. Though, that bouts of stubborn streak must have driven you up the walls at times, but I believe it'll help her fight for herself while growing up. By the sound of it she's doing her own things at her own pace.
I hope she'll gain the necessary weights soon. Happy Birthday to her.
Remember doctors do not always know the best for your child. Believe me, my mother have had to fight against some experts' suggestions for me when I was young and she won the battles.