1) Yes, you an file charges against her for destruction of property and vandalism--there are likely several different laws she violated, but the easiest thing to do is to file a police report, describe the facts, and let the authorities figure out which specific laws she violated.2) You can sue her for the cost to recreate or somehow retrieve the information she deleted. Most information is *not* gone forever from computers, even if deleted, unless a special wipe program is used after deletion or the harddrive is physically damaged or subjected to a magnet. There are computer consultants who specialize in retrieving deleted information--you should bring one in. You can charge the consultant's cost, plus the cost of any administrative personnel or temps who have to manually retype or re-enter information from paper records or from getting the information all over again from parents or teachers.3) If she had a non-competition or non-solicitation agreement which would prevent her from taking customers/students with her, you could sue her for breach of that agreement, seeking either or both of a court order prohibiting her from doing this and/or monetary compensation. However, if there was no such agreement, she is allowed to convince the students' parents to go with her; free competition is the general rule of the land, and an employee may compete with her former employer and/or solicit their customers unless there is a written agreement to the contrary.(If you don't currently make employees sign non-competition/non-solicitation agreements, by the way, you should do so in the future. You can even requires existing employees to sign them.)