MB is upset for a misunderstanding

I came in to work today & mb said she only pumped 5oz for NKs bottle. She said she was going to thaw some more milk. She went to go finished getting ready and I put NK down for her nap. I didn’t want to leave the thawed milk out (4oz) on the counter..

So i went ahead and added an oz to each bottle (theres 2) so there was 2oz leftover. I thought she could drink it the following morning.. soo.. i put it in the fridge

MB comes out and says what did you do with the milk? I explained to her my process and she blew up. She was like “why would you do that ?!” She wanted the 4oz in its own separate bottle

I was just trying to be helpful! I misunderstood what happened. This is my first time ever really messing anything up and I feel so bad. She said I wasted the milk :/

I told her I was sorry. What would you guys have done?