What did young mothers do way-back-when, before baby formula was invented? They made their own.
1 can evaporated whole milk. (13 oz)
18 oz clean water
1 tablespoon of light Karo syrup.
Done and done. If the kid is having loose stools, back off on the Karo a bit. Carnation still makes evaportated mild, and Karo still makes syrup. It's what generations of kids were weaned on.
I'm just saying.