Should we get into trouble if she signed a contract?

My friends mom signed a contract saying she could go to Florida with me and my Dad. A week later they fought and now my friend lives with her Dad even though her mom has legal custody. If her mom wanted to, could my me and my Dad get in trouble for still taking my friend with us even if her Mom was simply mad and said she couldn’t go? For example, say her Mom called the police, saying we took her without her permission and we showed them a contract, could we still be in trouble?