Is she is happy and seems healthy I wouldn't stress hun.

My DD didn't start eating properly until 8/9 months. She is 21 months now and only weighs 9.4kgs. In the past 12 months she has only gained 1kg. She is super busy running around though and eats when she is hungry. She is happy and healthy and I think she has her Dad's awesome metabolism! (Lucky her!) Just do what you can but if you feel something isn't right, maybe take her to the Dr hun for another opinion BUT there are many bubbas out there who are just smaller than the "average" baby.