Hi, My Baby Was Born In 7th Month (premature) Now

Hi,
My baby was born in 7th month (premature) now she is 6 month old and i am giving her dexolac special care milk powder but her wight is not increase please suggest and i spoke to one doctor they advice me to use dexolac stage 2 now and allow me to give proper food to my baby like rice, kichdi and all.
Please tell me which milk powder is good for her and how she can increase her weight she is only 6kg