OK. So after sleeping on it and talking with her sister, she was feeling much better about her remaining choice. She went as predicted and when she got back last night she was thrilled - it was great, they were wonderful, she was so excited and also fearful they might also not invite her back
I tried to reassure her and we waited for this morning.
There was a short delay but she finally did get her schedule - and she was invited back for Pref! I reminded her they wouldn't (or shouldn't) know they're the only group she's invited to so be mindful of that. She should be open and honest and soak it in - see if they really fit her and she really fits them.
It's been a bit of a long week, with ups and downs. For now we're coasting. I just want her to be happy, as happy as her sister was 4 years ago when she found her home.