Margarita's place was lovely, very clean apartment, very spatious rooms, everything one might need for a lovely short stay - fully equipped kitchen and bathroom(washing machine with detergent and all). The terrace is a big plus as it overseas the city and is a perfect place for morning coffee or summer beers. The flat is 5 minutes walk to a big supermarket and the bus station. You can take the bus to the sea side for 2euro one way and in 15-20 minutes you are at the beach. Margarita's parents waited for us at the apartment and were very nice , we managed to understand eachother fine even though they do not speak English.
The best way to get to the flat from the airport is via Uber and it will cost 9-10 euro. Uber is also the best choice for getting home from the city center at night.
It was a perfect stay in Porto for 3 days- definitely would recommend both the flat and the city - Porto is absolutely amazing!!!