I loved the old Republic comics, where they both appeared. I was just curious if that relationship survived to the new canon. I checked Wookiepedia and the references in that regard are from Legends. It’s been a while and I can’t remember if they ever mentioned it in Dark Disciple of Clone Wars.
As Wookieepedia cites, Ultimate Star Wars and Aayla's Databank entry established Quin as Aayla's Padawan in canon.
Is that the canon-specific Databank, or the one that Wookieepedia considers canon because it stayed up for a time after the Legends announcement?
It is indeed in the canon Databank - you can find it here by scrolling down to the "History" section. (The non-canon version that Wookieepedia considers canon is called the Encyclopedia, which itself derives from an earlier iteration that was also called a "Databank," so any confusion on that point is entirely warranted.)
I think you have that backwards. Both Wookieepedia and this page on the official site have Aayla as Quinlan's padawan.