Your child should have added about 2 Kg to his birth weight at two months. Since we don't know his birthweight, we cannot say if it is OK or not. You need to monitor your child's weight to make sure he is adding weight and not stagnant or dropping his weight. If there is no weight gain or weight is dropping, please kindly take child to see a paediatrician as soon as possible.

Your two month old should be on exclusive breastfeeding. The mother needs to eat nourishing and healthy food, ensure baby is well attached to the breast and empties one breast before switching to the other. You do not need to give a child any other thing to add weight.