Cancer eye can start on the eyeball itself, but more commonly it starts in the third eyelid or the bottom eyelid. The growths then can irritate the eye, causing watering, grey color to the cornea or ulcers. The pink tissue at the front of the eye is the third eyelid and it is hard to tell from the picture but it looks a little bumpy to me. That can be because it is a bit inflamed from something in the eye or infection (there is infection fighting tissue in there like in lymph nodes that gets bigger when needed) or it could be an early cancer eye. If you run her in a chute and run it between your fingers, it should be soft. If you feel a lump or hard area, it is probably early cancer eye and it should be treated early. Cancer eyes on third eyelids are the best kind because you can remove that eyelid quite easily and get rid of it. Ones on the eyeball, you remove the eyeball and if it is early enough you saved her. Ones on the lower lid are hardest because it is really hard to get it all and then the eye won't close properly. Too late on any of them and it has spread. I would check it out soon for sure. If you can't, get it to a vet. At that size, you have a good chance of fixing it permanently pretty easily (and cheaply) compared if you leave it.