We arrived early evening and unfortunately could not be welcomed by Maria, Sandra's mother (and cleaner!) though happily we did meet her on leaving.
The apartment was easy to find and as everyone else also says, is very clean, well-equipped and well-situated for on foot and public transport exploring. A handy transport option is the Viva Viagem card €6 pp p24hr.
Have to note that the flat is quite noisy because of its location. It was still pretty cold at night during our stay, so we didn't need to have the windows open.
For eating out, would recommend the Ribeira food market and restaurants Cantinho do Avillez and Ibo, all within 10 minutes walking distance. The latter has a bit more up-market ambiance, but would be a good venue on a sunny day, with its riverside terrace. Food and wines we had at both were excellent. Also, enjoyed Rio Grande (v. nearby, cheap and cheerful with a 3 course with drink menu for €7,50 pp(!). It was frequented by locals and tourists alike and was our first, pot-luck (and for us), late dinner stop.

Overall, Sandra's apartment is a very good place to stay and can recommend!