Advice needed please..

My girlfriend and I have been together for a while now and we are generally a happy couple. We have our arguments but we work through things very quickly and we are happy again. She has a short fuse, and I definitely know I get on them quite often, but everything is resolved quickly. When we get mad at each other we let each other walk away for a moment to calm down, we will gently touch each other on the arm or back, nothing too assertive, but just things to let the other know we are here. But today she isn't mad at me, she's mad at the people she works with. And she's been wanting to quit for a while but she doesn't feel like she should. Her fatal flaw is being too nice, she wants everyone to be happy, even at her own expense. Anyways, today when I brought her lunch at work she was very angry. She barely wanted to look at me, it was that bad, (also I noticed that she deleted our text messages, which she has never done the whole time we've been together. This isn't that big of a deal, just another reason I knew it was bad..). I know she didn't want to go back in and was dreading it, and I tried getting her to realize that she had half an hour to just take a deep breath and talk to me. I tried talking about what was wrong and just about other things. She didn't want to talk about what was wrong and anything else seemed to just add to her anger. By the time she left though, she kissed me (like, one that held love, not just a peck goodbye) and seemed to be breathing steady and I could feel that she calmed down but still wasn't happy. She's even texting me now calling me baby and other stuff, but I know she is still highly highly mad. I don't know what to do that won't add to her anger. I don't want to leave her alone because I know she doesn't want that, and I don't want to be right there because I know she doesn't want me to be "all over her" in a way. But, like I said earlier, she doesn't want to talk about the problem or anything else. I'm at a loss and could really use some advice..

(Also, I could really do without the judgmental comments about being with a girl, we are happy and peaceful. We are not in an argument, she is mad at the people she works with, not at me. Please and thank you).