Maria's apartment and service as a host was great. We did not meet her but she sent her friend to help us check in and was in constant communication. Her apartment has all the basic amenities. It was very neat, clean and functioned well. One mild warning is that the washing machine has a tight door so needs to be pulled harder than you might be used to. We were afraid to pull hard at first because we didn't want to break it but figured it out after a while and Maria sent her friend to help us very quickly.
The location is atleast a 15 to 20 min walk from the main city attractions. There's not much near the apartment. I would recommend Maria as a host for your stay in Seville!