One thing that seems weird to me is if she didn't carry her camera with her and if she was only using her phone to take pictures, and if she solely traveled for photography purposes why did she take so few pictures?
I'm an instagram user myself and I can not take pictures on a regular basis when I'm busy, but there are days when I say "today it's only shooting day" and I take tens of pictures. And many instagramers do that. Check out Her Amsterdam friend Ammer's photo feed on instagram for example. You scroll down tons of pictures to see the pictures taken one week before.
There are a few pictures of Amsterdam, few pictures of her Istanbul visit before Amsterdam and unfortunately very few after Amsterdam. No plane pictures, no skyline pictures, nothing at all from Munich. That seemed very strange to me as if maybe taking pictures is like a secondary intention or a disgusie for the real intension.
Another thing, I've pasted her conversation with Ammer here last night. The first time they exchanged the idea of visiting each other. It was only 5 weeks before today. If she was planning this trip for a long time, how is that possible?