Overall we had a good time in istanbul staying at Zehra's apartment.
My family wanted to stay where it feels like the movies and tv shows they have seen about old suburbs of istanbul. Although you live in an old part of istanbul I think the house is newly renovated so you're not living in an old house.
My wife wanted to eat authentic Turkish food and this area has plenty of little shops and home cooked meals. I would strongly recommend you to try Mevlana Ev Yemekleri.
Zehra is very practical with problems solving and communication wasn't slow so we didn't experience any difficulties while we were staying there.
Other great thing about this place is the proximity to lots of great attractions in istanbul like Sulta Ahmet cami, Topkapi palace, Misir Carsi.
The only cons is you won't find taxi right in front of your door and that's the price you pay for staying in such a suburb. But that problem is also easy to solve, you can walk a short distance to Medipol University and find taxis there.