I took a step back and told her, as she continued to complain, that she could talk out her problems or just sit there and do her work. She chose option A and told me she was upset at her mom and another teacher who was unfair and embarrassed her in front of he last class. I allowed her to return to her group.
Some days I just don't have the bandwidth to care about all of my kids. She was a Tuesday-Thursday child on my care schedule and she chose to have a bad day on Monday. That's what I was thinking at first. The reality is that we have to adjust to our kids and listen to them because we may be the only ones who do.