Claire West

Claire is Helen's twin sister, but she doesn't seem to have any superpowers.

Unlike Helen, though, she is geeky - wears glasses and a lab coat, and is interested primarily in the science behind powers.

Of course,  people have noticed that this is actually an advantage and she is quite often sent out to get a takeaway or run errands thanks to the fact that she cannot be traced by Vigilance... well, probably.