Some not-so-good news
Well, the vet called yesterday with the results from Boo’s test. Turns out it was in fact part of her mammary glands, and the tumor was malignant. So now the vet wants to check her out next Friday to make sure everything is going okay, and wants to do some x-rays to make sure we got all of the cancer out. The next problem may be uterin cancer, which I guess is a very common problem in bunnies. There is also a possibility that it originated in the uterous, and spread to the mammary gland, so that would be bad as well. The vet suggested that I get it all checked out with the x-ray, and then if everything looks okay to go ahead and have her fixed, to avoid her ever getting uterin cancer. So that’s the update on the bun-bun. 
Here’s hoping they don’t find any more!!