Diane was a perfect host and her house is indeed very charming.
Location: Diane's house is in a very nice neighbourhood in Mission Hill. It is quiet and within walking distance to the Old Town Transit Center, which is convenient if you want, as I did, go downtown by trolley (the walking path is not illuminated and therefore only recommendable during daytime). Presidio park is very close and looks nice but I did not have time to make use of it.
Accomodation: My room was nicely furnished and I had a bathroom for myself. Everything was clean, well functioning and without any problems. Diane provided me with towels. The house is nicely furnished with a big kitchen that seems to be fully equipped (I only had breakfast and used the oven once to heat-up a pizza).
Diane: Diane was very friendly and cooperative. She answered me any question I had (next restaurant, next supermarkt), provided me with fruits, milk, and cereals for my breakfast and even offered me to ride her bike. I enjoyed very much the few conversations I had with her.
General impression: Everything was perfect. I highly recommend Diane's place to anybody that visists San Diego and likes to be close to Downtown and/or the Airport but not in Downtown itself. I would not hesitate to rent Diane's place again if opportunity arises.