We had a lovely time at Hilda's appartment. The Coyoacan district is historic and beautiful. It is walkable from the appartment (about 10 minutes) and Monica (Hilda's daughter) was very helpful. She gave us useful advice about Mexico city and its environs, and as she is a tour guide was very knowledgable.
I would recommend Hilda's space very highly and Mexico City as a destination to anyone.