Hi, this is my first post.
I'm a "foreigner" of a similar age to Sarai and have been living in Istanbul for five years. I've been following this case with sad interest. I'm also into photography and often go around the city alone taking photos.
I've walked the length of the walls, at least from Eminonu to Kumkapi, on several occasions, but always on the water side. There are very few tourists around that area, despite the proximity to Sultanahmet and Topkapi Palace. It's also worth noting that leading down to the water are big rocks, sloping down. Couples tend to go there, also people go there to drink beer, as well as fishermen. You can't see people there easily. Maybe Sarai climbed on the rocks. Kennedy Caddesi isn't easy to cross, there's a lot of fast moving traffic and if I recall correctly, there may be barriers to prevent pedestrians from crossing everywhere. Perhaps someone can confirm.
I'm bothered by the spare shoes. From the CCTV photos, it doesn't seem like Sarai was into dressing up really nicely on this trip. It's certainly a faff carrying around an extra pair of shoes. As someone who's into long walks and photography, there's no way I would carry another pair of shoes unless I had a reason, such as a plan for later.
Also, after five years of living here as a foreign woman, I've learned a lot about the differences between Turkish culture and others (I'm British, not American, but we're somewhat similar, I'd say). You do need to be more reserved here in opposite sex friendships. There are also men here who seek out foreign women online, perhaps for visa reasons or for easy sex (or so they hope).
It is a horrid feeling to think of that poor woman suffering in that awful place, and now some parts of the Turkish media, as well as others, painting her as a spy and insinuating she may have been a drug mule, it leaves me with a nasty feeling in my stomach.