Ana's unit is a great place to stay in Ciudad de Mexico. She is also a wonderful host. Santa Maria la Ribera is a neighbourhood with nice shops and vendors. It is a little bit of a walk to public transportation (approx. 10 minutes), however, I enjoyed my daily walks past the fruit vendor every day where for 20 pesos I would get a huge cup of fresh cut fruit including the tastiest mangoes that I have ever eaten.
I highly recommend staying with Ana and look forward to my next visit.