She, in a very round about way killed her first husband Barry. She pushed him and he fell off the cliff. She then sat and watched him die, and very coldly told him his son would be better off without him. Technically, she didn't kill him but she made sure he died and showed no remorse for it. Never has done to this day.
I loved Janine when she was bad to the core, and I think possibly her best days are behind her. If Charlie Brooks does leave, they should write out Janine with a blazing storyline. She might not kill Michael herself, but I think backed up against the wall she would gladly let someone else do it for her. This was the man who drove her away from her daughter, and totally got inside her head and messed her about. She won't forgive him, and I'm sure the mind games won't end there.
As for Danielle, well it was an accident. The silly girl stood in front of the car.....