Oh my gosh, hon, that isn't what anyone would ever want to hear. Do you have other options? Is there a veterinary school near you that will work with you? (I know in my area, Purdue Vet School will sometimes take on unusual cases for teaching purposes pro bono, to use for teaching, and it's the best med care in the state you can get for you horse).
Keeping my fingers crossed for you and your girl that you find a solution! Best wishes, that's really hard news and certainly a big shock to deal with. *hugs* to you.