If you know the file name, then just type that in the search box. If you don't, but you know the member's name (if you're looking for an avatar), you can go to their page, which I imagine is what she did.
There's also https://library.tarvalon.net/index.php?title=Category:Avatars if you just...
Welcome back!
Since these new boards have square avatars, and the old rectangles look squishy on them, here's a square version of your old one.
https://i.imgur.com/CmncskA.jpg