What to do?!

Nika
My mother and sister in law say that they will only watch my daughter if I give them formula to give her. Mind you, she is exclusively breastfed and myself and my husband are military and we have drill. What should I do? I told them I would even put it in bottles and we won't be gone all day. Just from 0600 to 1800 maybe. I'm hell-bent on not giving her formula. So what should I do?