Your baby girl should be fine. Start in small amounts. But make sure you talk to your pediatrician. My friend gives her son Almond Milk, instead of regular milk. I think the almond milk tastes better than soy milk. Although if Ur girl has nut allergies of course don't give almond milk
Im not sure about soy. Have u tried Lactaid?? Its lactose free but still has the Vitamin D that she needs for nutrition. Thays what my daughter drinks.
I started my oldest at 11 months on whole milk, just gradually do it and I'm sure she will do fine :)