Caregiver keeps topping up the bottle because our 3 month old 'still looks hungry'

We leave the day's feeds measured out and labelled before we go to work. The caregiver has decided the labels are suggestions. By 4 pm everything is finished, the baby is unsettled, and the evening starts with a negotiation about where the rest of the milk went. Our doctor says our daughter is gaining well and the amounts are fine for now. The caregiver has looked after many more babies than we have and is not very interested in what a sticky label thinks. How do you have this conversation with someone who is far more experienced with babies than you, without her concluding that you don't trust her?