Nope, it's Chastity the S.H.I.E.L.D. agent from Elektra: Assassin. Dagger was much more childlike in her appearance, her hair was white rather than blonde, and her earrings were white daggers rather than one big golden cross.

Oh my word, I've just realized that Dagger must have formed a large part of the inspiration for my fantasy novel character Knife. Name and everything. *facepalm*