dd 22 months old superactive but thin question about formula and health drink

dd is turning 2 years old in 2 months.she is on lactogen 3 twice a day(total 18 oz) and takes fruits(banana, apple one each, raisins, orange juice, biscuits*(1/2), rice dal veggies and fish/chicken /mutton twice a day).2 eggs every week.she is super super active but hardly gained any weight after her 1st birthday .we moved to india after her 1st birthday and she stopped taking gerber and earth's best jar food completely by 14 months and was on normal diet.I am pretty worried that she looks so thin and still can fit in her 1 year old dresses ands tops.she is 33 inches tall. everyone says she looks small for her age and I also see her head abs overall structure is smaller than other infants. she is very smart ans cleaver otherwise but does not talk fully. she understands everything though.is this lactogen 3 which is causing this poor weight gain. should I switch to Nan or Pediasure? any suggestions for horlics junior or compan etc. please tell me which milk and diest plan is good for her ?her doc says all formula are the same and he is not realy giving me any advice to help her gaining some weight.