Breastfed baby/bottle ounces

Hello! My baby girl is 13.5 weeks and is primarily breastfed. We use bottles (pumped breastmilk) occasionally for when I’m not home and someone else needs to feed her or when we’re at an event and it would be challenging to breastfeed her. I’m struggling with knowing how many ounces to feed her in a bottle. Of course, with breastfeeding, we don’t really know how much milk she is getting during each feeding. I can take a guess of about 4-5oz based on my pumping sessions, but I’m not sure. It’s hard to read her cues with the bottle to determine whether she’s had enough or is still hungry from what I’m feeding her. If she cried right after, I’d assume she’s still hungry but she doesn’t. She seems ok but I’m not sure that she’s really getting a full feeding. Any advice on knowing how they’re being fed the right amount of ounces with bottles?? Thanks!!