Staying at Handan's is the best chance you could get when visiting Istanbul.
We stayed there 10 days and felt warmly welcomed. We had the chance to meet with some of her friends and experience Turkish food. In addition, she is extremelly cheerful, very patient (as we asked many questions) and generous with information and guidance!
As for the appartment, it is hugely big and each room is nicely decorated. It is in the heart of the Asian side, which I will recommend if you want to experience a more local life as opposed to the touristic and turbulent one from the European side. Ten minutes walk to the ferry and so close to the European side.
In three words as in hundreds: go for it