Colostrum for diaper rash?

So I’m watching a 3 month old of a really good friend of mine and am 30 weeks pregnant. Her daughter has a super bad diaper rash that gets worse every time we change it. I’ve tried the creams but itsnot helping. I know breastmilk is supposed to be good for that but what about colostrum? Of course I’ve got permission from Momma but wanted to know if it’d even work