Health concerns can be expensive. I think it is important to make them as comfortable as you can financially as their guardian, but like dmcarty, you may not need to have the tumor tested.
Unfortunately, no one can tell you what the right thing is to do. I found great support from the site by sharing my experiences. And it really helped in those powerless moments where I had to decide the fate of my basenji. Please keep us posted on her and you as well.
🙂