21 months don't want milk and is fussy with the food can i give multi-vit? she's very big for her age 31 lbs can i give her the one for 2 years and up?

Multi-vit: A picky eater is not unusual at this age. Children's multivitamins are ok to give but i wouldn't give the 2yo vit until she turns 2. I would still present a well balanced diet everyday, in an non-pressured environment and try to get her to take 2-3 dairy servings per day in some other form (ie: cheese, yogurt, etc..). Of course all dietary issues should be discussed with your pediatrician.