I was told by my doctor that after your baby starts drinking a bottle, it is bad in an hour. Formula is only good for 24hrs in the fridge if it is not drank from and I think breastmilk is 48hrs in the fridge not drank from. But if the baby drank straight from it then reusing it can make them sick.

yea keep it out once you heat it and if in a 3-4 hrs she doesnt drink it..start over

you shouldn't the bacteria in there mouths gets in the milk and multiplies and can get her sick

I do that with my son, he's breastfed then gets formula afterwards since I don't produce enough and if he doesn't eat the full bottle I just keep putting it in fridge until he finishes it off