Silvia was very friendly and even with a short notice was able to have our 4 people group. With the short notice there were wee hardships with the communication (her phone had broken and I had internet only quite rarely) but we managed anyhoo!
The place is situated very near the Portela de Sintra station (1min walk) and most of the relevant buses leave from the station (other side).
The apartment itself is neat, clean, equipped with everything(cooking/shower/sleeping-wise, though oven was broken at the time) relevant except maybe WiFi. There was a cafe nearby with a free WiFi, but out of 4 devices only 1 managed to connect there..(??) and it was sort of slow even on the one. To us that was no biggie with the city otherwise having plenty of wifi-spots.

Well equipped market about a 3min walk away

All in all, very very nice place(entire apartment!) for the price