Thank you for the update, and I'm glad it went better than you feared. It's good to hear that you found her looking well, and it sounds as though you avoided major upset. That's great!
I was a trigger for my mother's anger and upset. I'm an only child, so I suppose it makes sense, plus we never had a good relationship.
That was why I didn't visit my mother for such a long time after she moved into the care home, as it was sure to trigger her. Move in day was horrid beyond belief and the nurse manager said she'd never seen anything quite like it (not reassuring). But, against all our expectations, my mother settled well, and fairly quickly, and was much more content in her care home than she ever had been at home, for years prior.
My visits at first would sometimes, but not always, trigger the upset and nasty comments. I learned things to do (take gifts, distract, maintain very carefully positive and calm body language, demeanor, and tone of voice), and things to not do (not mention certain topics, not stay too long, not accept commands to come to her room for a chat, not be alone with her).
As time went on, I was able to stay for longer visits, visit alone, and so on. We do have to carefully listen for her cue for us to leave, especially if she is tired or in pain, and just go, even if we have only been there briefly.
She hasn't said anything nasty, or gotten distressed by my visits, in well over a year now, maybe longer. So it can pass.
I also had to learn coping techniques for me, for the visits. Music in the car, breathing exercises to stay calm, a lot of strategic retreats to the toilet, planning something pleasant for me after a difficult visit with her, and so on. I can talk more about that if you like.
Three years after she moved in, I still get upset about visits, but not as much or as often, and I have less dread and stress about them overall.
I hope it can be better for you, also.