Go from the prisons through the side exit to the docks and jump over to the mainland, it's the easiest path with the least amount of enemies, i've found. i have used this method successfully in the last few weeks, so unless update 23 broke this too, it should still work.
If you have an invisibility scroll, spell slot or potion to spare, you can also just cast the spell or throw the potion at her and walk out through the main entrance without anyone noticing.
