Hatice's place is exactly as described in the pictures and even more beautiful than the pictures. The view from the windows (sitting room, bedrooms) is absolutely priceless. You can just sit there for hours and hours looking at the Bosporus. The place was sparkling clean and had all the amenities you would need on a holiday (even more). Hatice is a great host, she replied to my questions/messages promptly and provided us with detailed guidance to the area. Her tips were so helpful.
There's a small supermarket 2 minutes walk and a mini carrefour less than 5 minutes walk on your way to Istiklal street. The place is about 6 minutes from the bus stop and 8 minutes from Şişhane metro station/Istiklal street.
The only negative point about the location is that later on we discovered it was unsafe. On one of the days when my friend was coming back to the apartment at 8 pm, on the main street leading to the apartment building, she was approached by a thief who tried to steal her phone (but she held on to it and he couldn't take it). When he couldn't steal it, he ran towards the street where the apartment is, therefore she couldn't go back there. She asked a man on the street for help to accompany her to the apartment building, but he refused (weird!) saying it's a very unsafe place and he wouldn't go to that street. Then the guy in the nearby supermarket helped and walked with her till the door of the building. I was on a 3-day trip in Southeast Turkey and my friend was there on her own. Of course the following morning after the incident, she stayed in a hotel for the whole 3 days until I got back because she couldn't walk back there again alone at night. I would say it's not convenient for solo travellers.