We are visiting Istanbul in a few weeks. I'm looking for recommendations for group or guided tours for my wife while I am working.
Have you read the RS Istanbul book, it is a great book to take with you to Istanbul for reference and guidance. Also, there are guides he recommends that you could contact to take your wife on guided tours. Also you can call the RS office and ask them for recommendations if the guides in the books are booked. Also ask about Yaren, if she is not in the book. She was our RS guide when I took the week long tour of Istanbul and she was very good. She guides privately too.
I am in Istanbul right now and we used Efendi Travel for a day tour and for our airport transfers. There are lots of companies to choose from, but this company was quite good, arrived on time, provided a great guide and was well-priced. They offer lots of tour options and travel around in groups of about 8 or 9 on a small bus.