Board Thread:Skyrim/@comment-10989287-20130619190600/@comment-7153552-20130619192030

It might be her way of attempting to off you. I've never actually encountered her trying to kill me, in any fashion. I have five seperate main quest completions and never even seen her, much less had any problems from her. I figure the gods of RNG just decided that's how she'd attempt to kill you.

However, to your credit, yes that is usually why you see hired thugs. When you piss off a character they do send folks to fight their battle for them. As for Shavari, according to her page she's supposed to confront you in Riften. I'm not sure where you were attacked, but it stands to reason that she might have sent someone after you outside of Riften so she could stay there and do whatever it is she does while she waits to confront you.