My baby girl's birth weight is 2.4 kg. she is a preterm baby born at 8 months. Now she is 4 months old. and her weight is 5.5 kg. is it normal?

A. Yes absolutely in fact I would say that your child is gaining very very well as per the fact that your child is a premature child born with less sweet but your child is doing very very well with whatever feeling that you are giving to the child