I used to take my son to the bathroom on a regular schedule, say every hour.
He was a little later getting trained than some.
What worked best for me was an idea I read about. I put a jar of M&M's on the vanity. Each time he used the potty he could have a couple. (This was a huge treat: we didn't have any junk food normally). You can use whatever would be a huge treat for her.
I think it could be anxiety (I've read some of your other posts and family events surely affect kids in ways they can't express or understand) and it could be just getting out of the habit as well as waiting too long. Taking her regularly will help her get back in the haabit and she will feel good about her successes too!