We had a wonderful time in Lisbon and we won't hesitate to contact Mariana when we come back. Even though we'd haven't had a chance to meet her personnaly, we communicated with her by texts and she always answered quickly and precisely.
The flat was extremely well located (5 minutes from metro station, 20 minutes walking from Bairro Alto), and was perfect for the two of us : its comfy, clean, easy to access.
We gladly recommend it.