My baby girl now 4months old she didn't gaining weight her weight is 3.6 can u help me

A. Namaste Mom A full term baby is expected to almost monthly gain in the range of 400 gm to 1 kg and by the age of 4 to 6 months they double their birth weight. You can take a healthy and filling diet or meal before baby feed time as such as that would ensure a good quality feed as such and that would help in weight gain