Cristina's place is easy to find, it is close to Plaza de Merced, right behind the house where Picasso was born. It is a nice and comfortable place to stay. There is a bakery, some other smaller stores and a small market right beside the house so you don't need to go far for some breakfast. But better not to do it early as shops open according to Spanish time.
During our stay we had an issue with the canalization but Cristina was helpful. It is very easy to communicate with her