Mixing pumped milk?

avalovesart

We have our first babysitter tonight (yey!!!) while DH and I got to a Cinco de Mayo party for a few hours. I've only ever left LO at the church nursery for about an hour, so she only needed about 4 or 5 oz of milk placed in two bottles of about 2 or 3 oz each. Tonight I'll need to leave a few bottles. Can I mix milk from different bags/pumping sessions in order to leave a bottle that is 5 oz? I don't have enough nipples to leave more than three bottles, but three bottles at 2 or 3 oz each won't be enough.