I am so sorry. Please do not have her leg amputated. She is young and this is fixable. I know the cost is crazy, but you can find a way!!
There is an awesome vet in Houston who you can go to...he is expensive but perhaps if you go there and talk with him he can help you out. His name is Dr. Beale and he is at Gulf Coast Veterinary Services at Post Oak and the 610 loop. I have used him for many orthopedic cases and he is the best! They do take Care Credit. You can apply for that through them...or go online and do it before you go:
CareCredit Healthcare Finance - Payment Plans and Financing for Cosmetic Surgery, Dental, Vision, Hearing, Veterinary & Other Medical Procedures
There are other vets who will offer to do cheap fixes...make absolutely sure they are offering to do the same thing that a specialist will do. I have seen people look for and find cheaper care only to end up spending more in the end to fix the damage done by the cheap solution. There are some cheaper vets in this area who are ok...none that I would use but many do without an issue so you can ask around. Just please be very, very careful!!
Feel free to PM me if I can help you in any way.