i followed the same rules as i did with mixing breast milk....cold with cold, warm with warm. i always did cold with cold, mixed it and then warmed it.
I would not mix BM with formula at all, because if they do not finish the bottle that is BM wasted! It makes for a lot of cleaning but I made a BM bottle then a formula bottle, but that is just me because I had a low supply....
Re: Mixing BM w/formula
It's a GIRL!!