Me and my colleague stayed in Marilena's apartment for 7 days. It was a very pleasant stay.
It is a charming old apartment, beautifully restored with ceiling paintings and with original tiled floors. The apartment is tastefully decorated, especially the bedrooms have nice antique furniture and beautiful curtains, lovely atmosphere altogether. It is also a very quiet, especially the one bedroom facing inner courtyard, suitable for a light sleeper. The apartment is also very clean. Be prepared for some stairs since there is no elevator (the appartment is on the 2nd/3rd floor).
It was a bit chilly in the apartment in March, but this could fortunately be solved with the well-functioning heating (air source heat pump in all rooms). There are two bathrooms, the shower in the walk-in bathroom is not especially powerful but ok. Unfortunately, the field strength for mobile phones is practically non-existant in the appartment (as for me personally in most other parts in Ortigia as well, with its thick walls and narrow alleys: internet worked but not the mobile field). These I would consider the only disadvantages in the appartment.
The location is just perfect, we loved it. It is just ten meters from the sea and the small Cala Rossa beach, the perfect place for a morning swim (with sun until early afternoon). The location is also just a little bit off the main tourist routes, yet with many good restaurants nearby. Just around the corner from the appartment you will find the lovely Cala Piada, where they sell fresh light food like their home made bread, "piadas", suitable e.g., for a light take away lunch to the beach, and delicious tiramisu.
Communication with Marilena was very smooth and kind, and she also responded to us with no delay if any question arised during our stay.