Claiming tax credits?

I am trying to help a 17 year old girl. Her father has died, her step mother has asked her to leave her home (a static caravan but she is not a traveller or gypsy) because she reminds the stepmother of the father. She attends colleage claiming EMA of �30.00 per week. She works part time on the caravan park serving meals some weekends. Is there anything she can do to get extra money from the tax credits system maybe. She does not want to go on the benefit system as she wants to learn and just extra money from her part time job. Mother not interested really. Therefore the caravan site are offering a caravan for her to share with someone else but for rent. Please help with this one.