What could this be?

This little bump has recently been showing on Miss Kitty's nose. It's been there for as long as I can remember but it's just now to a point where I can really see it. It's white in color and hard like a rock, it doesn't seem to cause her pain because I can touch it, but not for long because she just doesn't like me messing with her nose. My worst fear is a tumor considering she's had it since I've owned her, and it's slightly larger than in the beginning. Please help steer me in the right direction.

First off, absolutely beautiful kitty! 


Here is a link with a detailed chart of possible identification and causes:

http://www.peteducation.com/article.cfm?c=1+2141&aid=204
 

I would lean towards it not being a cancerous/dangerous tumour, as they can look quite nasty. If I were to guess, I would think it would be a nodule. Most of the time they are relatively harmless. More details:
 

http://pets.thenest.com/subcutaneous-hard-nodules-cats-10049.html

I'm not a vet of course - I know it is a standard answer, but a genuine one would know best! 

 

Oh yes, she IS gorgeous!  Other than that, there is really no way for us to know what it is.  Those articles Cassiopea provided might be helpful, but can't diagnose for certain.  The only way you will truly know (if even then) is to have it checked out by a Vet.