I stayed 4 nights at Catalina’s apartments and overall it was a very nice stay. She allowed me to check in as soon as I arrived at 10am and was there to greet me. From Padua or Lesseps metro, it is only 5 minutes walk, and in a very safe neighborhood. As a solo female traveler, I never felt unsafe, even when I arrived back late.
My room had an interior window but surprisingly, it stayed quite cool at night. I also had a fan which helped air circulation! The entire home was very clean. Be aware that the walls in many Spanish homes are quite thin and as Catalina has two young children, a dog, and many neighbors, it can be a little noisy from time to time. Though the apartment is located outside of the city center, it is a very short (10-20 min) metro or bus ride away from everything you want to see/do.
Overall, I would be happy to stay with Catalina again and would recommend it to solo female travelers.