Sibel's place was spacious, bright, and clean. Located centrally and a few minutes walk from the station, it's very convenient to get around. The view is amazing, although there is a big construction site in front, but it doesn't block the view across the river.
The only thing was that with Istanbul's summer temperature very much in mind, one of my main requirements whilst looking for accommodation for my family trip was air conditioning. Sibel's apartment does have air conditioning, but it is located only in the living room, and the cold air struggled to get into the rest of the rooms. There's one fan, so we made do, but it could get stuffy, and it would have been nice to know this detail beforehand.
Communication during check in and check out could have been slightly better, but it's not a big issue. Regardless, Sibel was very kind and helpful, and helped us organise transport to and from the airport. Still lovely overall. Thanks Sibel! :)