We had a great time at Ela's place with our family. We were a bit concerned about the stairs, so she showed the building to one of our friends living in Istanbul before we booked it. The building is located in Nisantasi, a very good and lively neighborhood in Istanbul. There is no elevator in the building but the steps are not high (it has about 34 steps!), so we were fine with them. Ela let us check in to the place 2 hours earlier when there were cleaners in the apartment. We never saw her though. The place is as pictured. We had some difficulties cooking there as we needed pots and we could find only one small pot and lots of pans! So, if you don't want to cook and don't need pots it is not a problem! The only important thing that needs to be fixed is a wall mount for the hand shower. You can see its current condition in the bathroom pictures. Ela was very responsive all the time.
We will definitely consider staying at her place for our next trips to Istanbul! :)