hi, my 4 year daughter weighs only 10.5 kg. doesn't eat much. she eats scantily even the things that she love. i am very worried about her. her legs ache at night and she hits us in her sleep . she is very active and doesn't want to sleep or take rest. she wants to play all the time without eating much. we have tried giving her multivitamins but every time she gets diarrhoea. please tell me where am i lacking or what she needs to gain weight