Will cows milk be enough nutrition at 12 months though? Or does she still have to have formula up until a certain age??
Cows milk will only give the child calcium which is for healthy bones and teeth. That alone WILL NOT keep a child alive.
Do not stop the formula if the child is not eating breakfast lunch and dinner and preferably snacking in between.
Formula has all beneficial additives that replace food till a certain age. Cows milk DOES NOT do this.
There is no certain age you have to give formula to, it REALLY all comes down to if the baby is eating FOOD.
If the baby is not eating full solids, keep giving formula in between solid feeds. That way the baby doesn't starve. When you've put the baby fully on to solids, eating proper meals a day then cut the formula out. The more solids you give the baby, the less bottles it will need.
As for worrying about a three year ok'd with a bottle, don't stress too much about that now. If your baby does not want cups or sippy cups then she's just not ready yet. My baby isn't. As a child gets older, and becomes more understanding of things then remove the bottle can be easier because they're more persuadable. (generally) I personally don't see the point of removing a bottle from a child and distress it when its only a baby when that child is still fully attached to the bottle.