It was a great trip! nice place, beautiful apartment and Marta and her husband have been very welcoming. They give us good recommandations to visit Madrid.
There is a subway station (Tirso de Molina) very closed from Marta's apartment and also a supermarket but walk is possible too, less than a 10 minute walk from city center. The neighborhood have a lot of charm, popular with mixed cultures. We loved that.
If i return to Madrid i'll come back there!!