We had a great stay in Palma, and in Mallorca in general. Carla's apartment is located roughly 10-15 minutes by foot from Place d'Espana (and the main bus station) and about 25 from the historic city center.
Although we shared the apartment, we had our privacy when we wanted it. We had full access to the kitchen, and were provided towels. Don't expect any thrills, but the lady (Carla's mother in law) was extremely friendly and helpful, and the apartment had everything one would need for a few days in Palma.
Overall it was a great stay! Would highly recommend.