This is from Supergirl Annual #1, by Sterling Gates and Fernando Dagnino.
First off, Lucy Lane is alive. She absorbs the life essence of some guy, killing him, and gets reborn or something.
We see her growing up, and how she was jealous that her father always gave Lois more attention. We don't see any mention of her relationship with Ron Troupe, or their child, which is disappointing.
Six weeks after Sam Lane gets apparently killed, she enlists in the army. She gets injured when the Amazons attack, but Codename: Assassin, under the orders of Sam Lane, saves her.