I should probably clarify that Jean was not intending to kill anyone. Her intention was to "frighten the league" so all the hereos and their family members would be close to each other. She wanted Ray back (though I don't really understand this seeing as Ray was practically throwing himself at her anyways, but I guess insanity explains that away).
Though, things went south when she messed up and killed Sue, she lost it. She decided to burn the body to try to cover it all up. Then she hired Cap. Boomerang and sent Jack Drake the gun to protect himself, believing Mr. Drake would have been able to handle himself.
