I haven't met Beatriz but she organised her sister to meet me which worked well.
The flat looks exactly as described on the pictures. Triana is conveniently located just across two bridges from the old town and therefore just a 10 min walk to the cathedral. The flat was clean and cozy. All I needed for a short break. The bed was really comfy!
I therefore had a very good experience.
There was a high-season surcharge I hadn't noticed when booking the flat. Beatriz finally gave me a little discount because the price variation for 2 nights was significant. It's probably my own fault as I haven't checked the final charge. If you go over Easter: Pay attention.
Communication with Beatriz can only happen via airbnb. She didn't want to give me her mobile number for expenses reasons but only one of a friend.