Well as with any youth who sets fire the issues contributing to the behaviour can be very complex. I have worked for many years as a youth care councellor and the majority of my clients are youth within the foster care system. I do have some basic educational material I could mail off to you to assist you to help educate your foster child while awaiting therapy.
Education is key when dealing with fire behaviour.
If there is a juvinile fire setter program around in your community they would be able to use a program form that asks questions pertaining to her behaviour that would identify if the behaviour is crisis or curious. They would also be able to provide the educational component to. As a foster child there are a few other things that come to my mind that my hinder any educational fire safety interventions. Of course all these issues are important to take into consideration with any child. Once the child starts counselling sessions it is import the therepist gets to the root of the problems which is affecting your daughter.