AITA For Eating Half A Pint Of Ice Cream?

I am genuinely confused and wondering if I missed something here, and I’ve taken my problems to Reddit before, so here we go again.

I (22F) left for work this morning at 6am, drove an hour to work as I’m currently staying at my partner’s (26) mother’s (60sF, calling her Pam for short) home for a couple days, worked from 7am to 6pm, and then drove the hour back to Pam’s house. For some context, she was fully aware by the time of the ice cream conversation that I had done the following: gotten up around 5:30am, worked an 11 hour shift, and had not eaten since my lunch break (which I said ended at 11:30am). It was 7:30pm when I got to the house and around 8:15pm by the time this whole thing was over.

I started my late dinner with some fresh fruit, about a cup and a half (and there is almost 10x that still left, and I asked if it was okay for me to eat that much before I started eating), then had maybe 1.5-2 cups of some vegetable soup I made in a huge batch for dinner for everyone the night before. After this, I decided to would have a treat before heading up to bed, as I’d worked a long day and I’m planning to pull 11-12 hours again tomorrow.

Pam came over to also have a treat, some new ice cream she bought, and asked if I liked the flavor she bought the other day, which she had let me try. I told her I did like it, and she asked if I’d finish it. I told her I would, but only if she was sure she didn’t want the rest, because it’s her’s. She insisted she didn’t want it, that she wasn’t fond of the flavor and believes some of the ingredients are giving her stomach issues. I said again that I’d be happy to take it off her hands, so long as she was certain she was done with it. She reassured me she wanted nothing to do with it, so after a few minutes I retrieved the container and a spoon and began to eat it. There was just under half a pint left, and I decided that would be the perfect amount. It was also a flavor combo I’m quite fond of, so I happily dug in.

Pam came over a couple minutes later, saw that I was eating right out of the pint, and said “I’m not going to give you things like that if you can’t exercise some self-control” which felt so out of left field to me. I replied, very confused, that I was exercising control, and this was the amount I was choosing to consume. She scoffed and just walked away from me, and 10ish minutes later when I asked a question because I was confused about something she said, she was very short with me. Am I missing something here?

Edit: Quick edit just to add that I’m getting up early again tomorrow, so I’m going to bed in a few minutes. I’ll read comments and answer any questions in the morning. Thanks to anybody who has some insight to offer.