It's like a curse that says: "If thine name is Gwen, thou shalt have no character development whatsoever and thou shall strive to be so likeable and end up being such a bore." Or something like that. The other Gwen doesn't even get in the way of any shipping. She just... exists.

GO YOU! Actually Merlin isn't that easy since my favourite character changed between S2 and S3, haha.