My 5.5 month old baby girl could not gain a single gm of weight in between one month.she takes basically FM and a small ammount of BM. what should I do? I m getting so helpless

A. Hello mom babies by the age of 4 to 6 months they tend to double their birth weight and then on by the age of one year they triple it if the child is as a preterm baby then they tend to gain weight on a slow pace .. than compared to full term baby .