Maria house is great you can actually reach everything from her house and the river is directly in front of the house so that’s perfect for a walk, if you take the 75 or 41 bus which is less than a minute walk from the house you can reach everything in Madrid ( the city center soo, gran via, and many other places), in addition if you take the 46 bus which is just 3 minutes from the house you can reach the university. Maria is great host I meet her at my last days of my stay she is perfect, social, kind person, I am definitely coming to her house again in future+ Madrid is great :)