Can I keep tenant security deposit for insurance deductible?

[Woralak Bryant]

So my renter of 7 months called me up and said that her son and her nephew was playing with a lighter and fire started in the bedroom. She called the fire department and it's all under control. Everyone was fine except for my house. I told her she can move out because I don't know how long it will take to fix it. She prepaid until January. I will give her back the rent she prepaid. I would not charge her rent for Aug since that is the day of the fire. I also told her that I would keep $500 of the deposit if she moves.  She seems to think that she is entitled to the full refund. She keeps saying that it was God doing.  I am stressing out over this.  The law to my understanding said that they are entitled to a full refund unless they are responsible for the fire. This rental is in Illinois, if anyone is familiar with Illinois law please help me.