Solo Traveler in Istanbul

One correction: Turkey is not the "Middle East" - a small sliver of Istanbul is in Europe and the rest is in Asia Minor. Maybe that alone will make it a bit less intimidating for you psychologically. Still, it's an exotic place for many US visitors with lots of layers and diverse population - some are very conservative and others very secular, you'll pick up on that in the clothing and mannerisms. There are different neighborhoods in Istanbul that feel very different. If you spend time in the "New City" (Beyoglu/ Istiklal Street), I doubt you'd notice the difference between that and any other young, lively part of Europe. On the other hand, there are very old traditional neighborhoods, where you'll notice a striking difference and you may very well feel like an outsider (most tourists won't walk randomly to different neighborhoods off the beaten track like I did, though, so keep that in mind). In general, the Turkish people are very friendly and hospitable, there is no reason to feel like going there will make you unsafe somehow.

I've been there three times, spending about 3 weeks total or so, and would offer the following advice. Dress modestly (this will help inside mosques as well), don't call attention to yourself, and everything will be fine. As a young woman walking alone (and especially if you have light/ blond hair), you will stand out in some areas more than others, but honestly it's no big deal. You will have touts constantly trying to get you into their carpet shop or try to get your attention somehow. It's annoying, but not a safety issue. You have to learn just to ignore them, and you'll be fine. I had a fantastic time in Istanbul traveling alone. I would not hesitate to do it again. I think you will have less time on your own than you think during this very quick tour. I would arrive early and try to do some sightseeing on your own. Or, do it at the end when you feel more comfortable.

PS. Turkish Air is great (prices, service, food options) and flies from LAX, so you have an easy way yo get to your tour.

Well, I was almost 60 when there alone and I still 'stood out'. Just accept that solo travelling women in their culture is an oddity so they are just curious. I will admit, I like mirrored sunglasses to try and avoid eye contact with males and particularly touts. They will want to sell you carpets and invite you for tea. Supposedly, saying no to tea is a rude thing, but I have an agenda, things to see and do and I don't want to make time to either chat or look at carpets.
If you wander the markets, it gets difficult as 'window shopping' isn't like at home. If you pick up or finger the goods, or ask the price, they are more likely to think you are interested and start the bartering. So one has to toughen up and practice the bartering skills. Me, I wandered through a smaller market near the Blue Mosque, slowed down a bit and saw some prices, but generally decided not to buy....but then I really don't shop anyway. I did pick up yummy Turkish Delight but as that is a store, no bartering required.
Do dress conservatively, walk confidently, but have fun. I don't know where the hotel is, but once into Sultanomat (I am sure that is the wrong spelling - but, you know), everything is close and walkable and there are always people around. the mosques will have some sort of cover up to use if you forget some, but I would say, cover ankles, wrists, cleavage and then take a scarf to cover hair as you go in. I went in early March so coverage was no issue as there was snow on the ground ;-)

I haven't done this RS tour, but I've done 6 others.
I am absolutely certain you will get information before your tour, and from your guide on the tour, to keep you safe.

I did travel Istanbul and more of Turkey alone at your age and of course wandered away from my group at times when I assisted a couple of our Turkey tours about 10 years later. I definitely encourage you to go, and to make use of tips you get here and from the tour guides over there, but don't let these worries keep you from going. Men can be persistent with whatever they're "selling" but physical attacks on the street are not likely. Be careful about accepting invitations into secluded places, of course.

Thanks for the correction Agnes - and thanks everyone for letting me know about your experiences! This is definitely encouraging. I know the guide and book will have tips too but I wanted to hear from other women firsthand so I appreciate your responses. It seems that applying common sense is the most important thing, as it tends to be no matter where you travel. I know it's not as dangerous as people think - I went to the Tour Alum reunion this year and watched the presentation on Turkey with hearts in my eyes - but I was still slightly hesitant. I'm so happy they reinstated this shorter tour that I can actually take! I'm getting excited already...even though it's nearly a year away.