If they aren't interested in cow's milk, then have them bring you a carton of the soy or coconut or other type. That's what happens here. I provide milk but if they want, I have space in my fridge for the other. The whole idea of formula is to replace breast milk for the under 1 yo, because they aren't supposed to have cow's milk till 12 mths, am I right about that? So I think everyone's right, get them to send in the formula premixed if necessary otherwise switch to something more age appropriate.