She started ignoring me...

I used ai to improve this text because my english isn't very good

My coworker and I used to close together regularly. When I arrived at the restaurant (we're waiters), we'd greet each other with smiles and hellos. Throughout the shift, we'd frequently catch each other's eye and exchange smiles. We'd chat, joke around, and help each other out. If I took a moment to get a drink of water, she'd often join me, and vice versa. At the end of the night, she'd accompany me when I went to grab my coat. While waiting for our colleagues to finish smoking (neither of us smoke), she'd sit with me and we'd talk. I'd then give her a ride home, and we'd enjoy listening to music and chatting.

But yesterday, her demeanor completely changed. She greeted our other coworkers normally but completely ignored me. She avoided eye contact all night, except for two brief instances. The first time, I noticed her looking at me. We held each other's gaze for a moment; I smiled, but she didn't return it and quickly looked away. The second time, she glanced at me while getting a drink. I smiled again, but she simply stared back. I asked if everything was alright, but she just said she was tired. Strangely, she interacted normally with everyone else, laughing and talking until I approached, at which point she'd distance herself. She didn't join me when I went for my coat, and instead of sitting with me while we waited for the others, she went to another room and stared at the empty reservation book. She still accepted a ride home, but she remained completely silent the entire trip, ignoring all my attempts to start a conversation. I almost forgot she was even there. What's going on with her?