My daughter doesn't want to go see her siblings in foster care?

A while ago I posted asking for advice about what to get my daughters siblings for presents here https://able2know.org/topic/567891-1

Because of the post I got the idea of taking my daughter on a trip to go see them this summer. Some people suggested that seeing them/hanging out with them would be the best present.

So I got in touch with their social worker and set up a date for late July. Her siblings are supposedly very excited. I had thought my daughter was excited as well.

However, yesterday my daughter told me that she doesn't want to go. Like at all. She has no interest in seeing her siblings. I also found out that she still hasn't been talking to them on the phone and is just pretending too. She says she would rather go on a real vacation to somewhere fun as we never got to go before. If we go on this trip I will not be able to afford another trip this year.

I do plan on bringing this up with her therapist to make sure everything is okay. Her next regular appointment isn't for another two weeks and I don't really want to set up an earlier appointment and disrupt her schedule. We still have a lot more time before the maybe trip to figure things out anyway and there doesn't seem to be any immediate cause for concern. She was a bit quiet earlier this week because she was nervous about asking not to go. Now that she's told me she's back to normal energetic self.

Anyway until then I was wondering about getting some more outside input. I know that people always say its important to keep siblings close and connected especially when foster care is involved, so that's what I've been trying to do, but what if one kids just isn't interested in the others? Its a bit of a pickle too since the other kids are interested.