From what I was able to dig up, it looks like this NPC has had a questionable history.
It'll be easier to explain going in reverse order.
"Chopper Bregna" was removed late in the game. A shaman guildmaster named "Bregna" came into existence at the same time.
Prior to that, but after the trolls took Grobb back from the Frogloks, it looks like she was "Chopper Blerga" (There's never a Chopper Blerga and a Chopper Bregna on the Grobb tradeskill supplies list at the same time)
But a complete list of tradeskill supplies in Grobb from EQTraders circa December 2000 shows that most tradeskill vendors - including Blerga/Brenga/Bregna - didn't exist prior to the Guktan invasion.
http://web.archive.org/web/200012162...ion/grobb.html