I understand completely about the financial thing, gas and groceries are compounding the problem for sure! ACL surgery at 9 years old is going to be very hard on her too. Is her leg stable enough for her to put any weight on it? If so there’s a chance she could heal on her own but you have to manage her very carefully. No running or jumping for at least 6 months leash walking and support care like an anti inflammatory like meloxicam and if you can find it shockwave therapy or laser therapy would help. I have had my dogs hurt their knees before and have so far gotten them back to full function but mine had partial tears not full tears