Unidentified Mutton......
Some posters might remember that thread.
Yeah-- she can be a challenge for a low level character. The most recent time I ran into her was with a totally new character. The alternate start mod I use can start a character in all sorts of different places, including up in the mountains, very close to Dive Rock. I wasn't quite sure where I was when I started (I also use a mod that removes the player marker from the map), until I saw that shimmering troll. She saw me about the same time I saw her, and since all I had at that point was a set of leather armor and an iron shortsword, I ran away just as fast as I could.
With the right equipment though, she's not that much of a challenge-- more than a normal troll, but not as much as, say, Ghola gro-Muzgol (what does Buffy call him? gro-Freight Train? Something like that....)