That is true, Nick, she did. Vader must have been put priority on finding her after their confrontation earlier this season. Perhaps since she was disgusted by the Jedi way, she could be swayed to become an Inquisitor and right hand (perhaps overthrow the Emperor)? But it still doesn't explain why the Sister was hanging out. All that was needed was a line of dialogue when she was with her probe droids (why have they come to my lair? or My leads have paid off). Who knows, maybe Wolffe is still a loyal to the Empire clone?
I think I'll just stick with calling the Inquisitors Brother and Sister (I keep thinking Seventh Son all the time).
I think it would be interesting to see how the Empire recruits Force-sensitives to become Inquisitors. I'm sure some of it is out of fear for their lives, but how they are indoctrinated, etc., especially if some were former Jedi... and maybe as I mentioned above altered so they don't appear as Jedi (since it would be odd that Palpatine would hire traitors to hunt down traitors... not that it ever happens in real life, right?) I doubt we'll see it if the show is called "Rebels" and not "Inquisitors." But, as I said in my previous post, I think it would be an interesting "twist" if the Sister is who you think it is, Nick, because her plotline was left open in TCW, especially with Palpatine's interest in her fate.