I know, Jes, you're right.
It was fine!
Picked her up, she was deliriously happy to see me (that's always fun) but looked fine, like she hadn't been crying, I went to the teachers and they both said they had read the letter, understood, I did some elbow-touching type "Oh good I'm so glad, she seems like she had a good day today," they (one) said "She was smiling all day, she's such a sweet girl", the other one (grabberwoman) was a little more huffy, though trying not to be, emphasized the part that parents need to leave fast, I said yes, I know, I made a point of that today, are we clear on the other issues? She said yes.
Sozlet got and gave a hug to her friend Bridget, which she always likes, and (this is the most positive development, from my perspective,) wanted to show the teacher (non-grabber) her new hat. That says to me that she's not just putting up with her but likes her.
We talked about what she did today, it was all positive things, and I also watched for about 10 minutes total (right after I dropped her off, and then before I picked her up) and she looked like she was having fun. So I think this hurdle has been cleared, though I'll continue to talk to her about always speaking up if anyone does anything that makes her sad or uncomfortable. (Yep, it's a tough one, dlowan. Explaining things using concrete examples is always best, but what concrete examples? How to avoid making her nervous about real people? Ah, so complicated.)
Thanks again for your feedback, everyone, helped a lot.