Hi Brownie and family, welcome. We are so sorry you found yourself here but are so glad you arrived and shared your story. Brownie has been through a lot and she sounds like a real fighter and has a lot of spunk, which is awesome.

I can't blame you for debating whether or not amputation is right for her, it's a hard decision made even harder when a dog is as mature as she is. What I can tell you is that many dogs in her age bracket and size have done well on three legs, and while there will probably be ups and downs during recovery, chances are good that she will do fine and go on to have a happy life with you. If you want to make the decision knowing you have covered all your bases, it would be helpful to get a second or even third opinion from a board certified orthopedic surgeon if you haven't already. 

Also, I'm guessing that your vet has not discussed electrochemotherapy or intralesional chemotherapy with you? If not, I would look into it to see if it's an option for the type of tumor she has. These two ways of treating tumors are commonly done in other countries but not here, not yet anyways. These processes have given many Tripawds a great quality of life when amputation wasn't an option. For more information please check out the links above and let us know what you decide to do. We will support you no matter what path you take.