How old is she? It can take a long time to learn to express emotions. I was terrible at it in my teens, still pretty bad at it in my 20s, and I finally feel like I am getting kinda okay at it in my mid-40s.
Be patient. Let her know that it is okay if she cannot explain an emotion today.
Consider the two of you keeping a diary of times that she was and was not able to express feelings. Maybe in the future at other times she can go through it and say "I feel like I felt when we wrote this entry", or "I think this word/expression/description describes how I felt then", or "I think this fictional character we are watching/reading is supposed to feel how I felt at this time". Maybe it will help her learn how to explain some emotions, or least help you identify in retrospect.
Pick a hobby that brings you joy, and then figure out how to get the easiest job that will support you doing that hobby.