If One of your coworkers frequently complains about problems she's having with a customer. You decide to?

I would first listen empathetically to my coworker to understand her concerns better. After that, I might suggest brainstorming potential solutions together or recommend that she seeks advice from a supervisor or a more experienced colleague. If appropriate, I could also offer to step in and help address the customer issue directly. This way, we can work collaboratively to improve the situation.