I'm thinking since Jessica and Lucas's dad is a well known business guy who is really firm and a threatening man, jessica is like that but more of one you don't notice. Jessica is a rich good girl, that's her image, but behind her actions, her words, there's bad intentions. So I think her being a bad influence in mercy the way of making mercy just like her. Mercy having the "good rich girl image" and using that to get away with her dark, chaotic actions.
They say that ...when you find yourself, try to become a better person, all your shitty friends ...well, they will be gone. God will not allow you to work on you, let you get better and heal and keep bad friends that influence you the wrong way. That is not going to happen. That says a lot for those that stick by you.