Oh, that's a lot of ifs....
I think you should try to meet up with her face to face before you consider this any further.
In the event that your friendship should turn into something more, you might not (and she might not) want to be living in Russia necessarily.

My advice would be to meet with her first, then if everything still feels right, discuss the idea with her and see what she feels about it.

If she is a young professional working in St petetersburg she probably knows the local job market quite well. Even if she is not in the same field as you, she is bound to know others who are and can help identifying the options.