First of all weight is one of the criterion and not the only criterion of health.if child is active who weighed approx 2.5 kg at birth and plays around a lot and is showing progress on growth chart then she's most likely fine.i routinely advise iron; calcium and egg white daily as a protein supplement and 1 banana daily .decrease milk intake to Max 350 ml per day.

At this age,give just 2 milk feeds including one top milk feed and 4 solid meals a day including curd and Banana in the diet. Give her everything you prepare at home,but stick to the above-mentioned diet plan. Weight should be double of birth weight at five months and triple at 1 year of age.