Picking up SD16 at Mom's in the a.m. has been going OK. I just sit in the car and text her when I get there. H did go up to the door and knocked the other day; Stepdad answered the door, called for SD16, and shut the door on H. At least H could laugh it off. And it doesn't seem like Mom or Stepdad are trying to "convince" SD16 that "she doesn't really want to go with us". I don't know why not; that's what they'd usually do in the past.
We all went to a school event for SD16 last night. We saw Mom & Stepdad across the hall, waited for them to go in the room first, then went in and sat on the opposite side of the room. Stepdad was his usual self, center of attention/super loud. H said that Mom looked rough. SD16 did come up to us and chat a bit -- wasn't doing the "if Mom is here then I'll pretend I don't see you" thing.
H has been texting with SD16 to plan some trips this summer. She is really excited about a couple of them and has given input about when she wants to do them. So that's positive, that she still wants to do things with us. I am coping with lots of anxiety about how this weekend (when she should be with us) she said she wants to spend all day Friday, plus Friday night, at Mom's (Friday is all-grades prom at school, and Saturday she has a midday extracurricular event). I can kind of talk myself down by putting myself in her shoes -- she said she wants to get ready at Mom's and plus she has her event stuff (a lot to lug around) at Mom's. The fear is still there, that she's just coming up with plausible excuses not to spend the night at our place, or that after her event on Saturday, she'll say something like "Can I just go back to Mom's, I'm really tired" or something. I am working to get in the headspace of "whatever she and H work out is cool with me" -- it's H's parenting time so if he's good with something then that's his deal.
Overall, I really have no idea what to expect at any moment. I am 1000% looking over my shoulder and waiting for the other shoe to drop.