I've managed to sneak all the way to the rat-way exit, only to have her pop up at the door upon exiting... she declares "There they are...", and even if I try sneaking away, or for that matter running away, either Esbern will zap her, or Kharjo (who's along for the ride) will cave her skull in. Reasonably enough, they don't seem to have much tolerance for filthy Thalmor spies. I've also tried sneaking up on her while still in the rat-way and using the 'Dismay' shout (Boo!) in hopes she'll run away... no dice. 'Paralyse' doesn't hold her long, as a poison or an enchantment... I've even tried givin'er a blast of the wabbajack to no effect.
The only other thing I can think of is to exit the rat-way without passing her... not being a member of the thieves guild, I can't go out through the cistern... is there some other exit back in the warrens? Could I use Stamina poisons on my bow as a sort of tranquilizer dart? If anyone else has managed to bypass her in some way I'd love to know how... otherwise I find myself (ten reloads and counting) at rather an RP impasse.