Someone said upthread that Jennifer Hetrick and Pat Stew were dating, but he actually had an affair with her while he was still married. It's part of the reason why Stewarts children no longer speak to him. Hetricks didn't make any further appearances in TNG because her and Stewart broke up after the 4th season if i recall correctly.
Frankly, I'm glad we never saw Vash again after 'Q-less'. Her performance in that episode was god awful.
"Pat Stew"?
I need to see Q-Less again. I remember her part being one of the best elements by far and she didn't seem to be phoning it in or anything. Her background made it easy to get her to the galactic train station there in a way that didn't feel as contrived as for a couple other characters from this period.
The one saving grace of the story is allowing an opportunity to really show how DS9 would not be a rubber stamp of TNG, and allowing Q to do show off gruesome things that simply could not be done in TNG. No YT video clip exists, since all the Q-Less ones are the silly boxing arena scene or when Vash and Q are first seen together, so here's the transcript:
(Vash is escorted from the assay office with a full rucksack.)
Q: Well, I'm glad to see you've packed. I hope you said goodbye to all your new-found friends.
VASH: I don't have time for this.
Q: You've led a charmed life these past two years under my benevolent protection.
VASH: I can take care of myself.
Q: Really? Do you remember that tiny little insect bite you had on Erabus Prime? If I hadn't been there (Vash has very little hair left)
VASH: I am not going with you.
Q: The galaxy can be a dangerous place when you're on your own.
(Vash gets nasty boils)
VASH: It's over, Q.
(Now she's deathly grey, bent over and falling to the floor under the weight of her bag)
Q: I leave you now to reconsider my offer of friendship.
(Q vanishes and Vash is normal again)
The scene's also got a great callback to TNG season 2, where space was a dangerous place and the Enterprise was doing more than glorified taxi routes, and TNG2 could only do so much as well, so DS9 really upped the stakes. On the plus side, that scene or episode didn't devolve into a clip show. So maybe it's two callbacks rolled into one.
Apparently, there were attempts to get Vash recurring on DS9, but it failed. A bit of a shame, but in later seasons with the Dominion War, it'd have been harder to do. Early on, more mileage could have been eked out, and considering how bleepin' awful the Ferengi were written in TNG but were given actual depth and life in DS9, the same could easily have happened with Vash. But, overall, the Maquis, Founders, and Dominion were better choices for getting a lot more out of this spinoff as well as not being tethered to TNGisms, something TNG learned with all the TOSisms. But by 1993, the popularity and zeitgeist had changed and DS9 would have fared worse if it kept all the TNG side characters for regular plot fodder.