Yes, a vet visit first.

Then if everything checks out, an enzyme cleaner like Natures Miracle. Try and block her access to this room if that is possible until the cleaning is done.
Several years ago my cats started peeing on a mattress, and it took WEEKS to get it clean enough for them to stop. We had to keep them out of that room. Putting down aluminum foil in between enzyme treatments helps also.

Good luck!