When you, your boyfriend, and your mother travel together, accommodation can be 'ehem a bit tricky. Everyone wants a bit of privacy but you also want to be close to each other... why else would you go on vacation together? Unless you are Paris Hilton, you also probably don't have one million dollars to spend on a swanky hotel suite. So, might I suggest that you turn to AirBnB. Rent an apartment for a few days and have more space, more coziness, and pay less than you would at most hotels.
We found this sweet place which is in a great location, walking distance to the main tourist hot spots in Sultanahmet. The house was really a bit too big for just the three of us but it was great in that we could have our own rooms and bathrooms and it also had a nice kitchen. After a long day of touristing, sometimes you just want to come home, relax and not be pestered by restauranteurs trying to rip you off. So, we bought some wine and cheese in the local grocery store and took full advantage of our kitchen to prepare a petit aperitif which we enjoyed on our rooftop gazebo overlooking the Bosphorus.