Crusader was the daughter of Steve Rogers (Captain America) and Carol Danvers (in Rogue's body) from an issue of What If? that posited 'what if the Secret Wars ended 25 years later?'. All of the heroes and villains were stranded on the Beyonder's world and had to survive, so they all hooked up and had kids. Crusader's costume involved her father's shield, a chain-link armor thing like Captain America, then the rest of the green stuff was due to the Rogue elements of Ms. Marvel's psyche. Mjolnir chose her instead of Thor's son, hence why she's got it hanging from her hand there. Sadly, I don't remember who had done the original artwork.
For this artwork, I particularly like the shading of the green cape and the shield, and I think that's the best rendition of Mjolnir I've ever done.