Hello and thank you for asking your question on just answer. My name isXXXXX will try to help.
Do you know how she injured it? Was she running around?
How much does she weigh? Is she currently on any other medications? I can give you the dose for aspirin.
Hopefully it is just a sprain then. Usually if there is a fracture, there is swelling and they refuse to put any weight on the leg when you try to get them to walk.
You can give her human aspirin for pain and inflammation. Aspirin is the only safe over the counter pain medication to use.
Her dose is one aspirin tablet (325 mg) every 12 hours. Giving it with food helps prevent stomach upset.
Try to keep her quiet and still. No walks until she is no longer limping.
She should be improving in 2-3 days. If she is not, then she will need to see her vet.
If she gets worse over night, and stops bearing any weight on the leg, then she should see her vet tomorrow for an x-ray.
I hope this helps.