Oh, I agree with everyone else - I respect your decision, but don't give up yet!
That IS a lot of stress - there are so many weird smells and sounds in nursing homes, and she visited a lot of people on her very first day. That can be pretty overwhelming for a dog's first time in a nursing home.
Honestly, it sounds like she did very well, she just needs to be a bit more comfortable and ease into it. At least she didn't do what Cooper did on one of his first visits....got VERY interested in someone's colostomy bag.
The lady just fell in love with Cooper because he laid his head in her lap, gazed at her adoringly, and breathed deeply. :p Only I knew what was going on in his little doggie brain!
Another thought to run by your TDI coordinator (or just try to rustle up yourself) is hospice visits, where you go to someone's home. There's a number of volunteer opportunities around here where they want people to visit with home-bound folks and just spend time, or do little chores & errands...when I have time I'm going to look into doing that & taking Cooper along.
One little tip: Take a non-greasy treat along. I use almonds, because they don't mess up anyone's hands. It might relax her if she has folks giving her little treats & taking it slow.
Good luck!