And how about a parallel universe Lucy Lane as Superwoman? There doesn't appear to be a Justice League in the Supergirl universe, so she doesn't have to be a member of the Crime Syndicate.
Pre-Flashpoint, Lucy Lane was Superwoman. Sam Lane had somehow developed a super suit that mimicked the powers of a Kryptonian, and Lucy used the powers it gave her to fight Supergirl. However, Supergirl accidentally destroyed the containment field that made the suit function in the battle, and the energy release killed Lucy.
When Sam Lane and Maxwell Lord were together with the power source at the end of the season finale, I was thinking, "Ah, so are they going to develop the Superwoman suit?"