Hi Crystal,
It’s hard for me to say for sure without observing the behaviour firsthand but yes you can certainly walk her outdoors without doing any training just to give her exposure, so long as it’s not making her more upset. Do you know what caused the fearfulness in the first place? ie. was there an event that triggered it? Think back to the time between when she was fine and when she stopped being fine for ideas.
If you’re practicing with her, make sure your other dog is in another room (if you’re practicing indoors) or leave your other dog in the house if you are practicing outside.
Darcie