I's been a while since you watched Voyager, huh?
That's where you know her from, she had the ridges on her nose then <g>
She's been here and there in sci fi since, but I don't know when the last time I saw her was. It's been a while (I'm sure she was doing other stuff, and raising her kid, but I don't watch much that isn't sci fi/fantasy
No, it's not different to me because Doctor Who tends to reuse cast (Gwen of Torchwood was Gwendolyn of Doctor Who in Unquiet Dead, Freyma was Martha 2007+ and 'her cousin' in Doomsday -2006) etc, and most shows I watch from UK TV tend to use the same folks as well. And as I mostly watch science fiction/fantasy, there is certain smaller recycling of the same cast, on a much lower scale both from Hollywood and Canada. (SG1, Sanctuary, a lot of the same actors, even Alpha's has a government no nonsense agent who was no nonsense cop in Dresden Files)
Hollywood tends to want 'name' actors, folks who appeal to fans of the genre, and UK says "We only have so many actors". so it's all the same to me.
I'd say that moving to Starz gave Torchwood a much wider casting pool, but they have obviously enjoyed going for names that had 'previous appeal' for lots of cameos.