We did not meet Gwendalina in person (we were received by a friend of hers that showed us the way) but she was extremely helpful, recommended good restaurants in the neighborhood (ask her about eating fish at the market!) and helped us book a taxi - all by sms and phone communication.
The apartment is in an old and charming (a bit run down) building, but it has been recently renovated and is lovely, perfect for a couple (only con: it is on 2/3 levels and the stairs are a bit narrow, as shown in the pictures). The terrace upstairs is perfect for having breakfast and enjoying the view (and the noise of the market!).
The location is ideal, right in the old town at 1 minute walk from the cathedral. Although the neighborhood does not have the best reputation, we found it safe and (in the summer) always full of people. Recommended!