I had a cat that never once covered her litter years ago, I guess my family never really made a big deal out of it. I wouldn't worry too much about it and just let her do what she does. I am sorry, but I doubt there is anything you can do to teach her to cover it, if it smells bad you could invest in a box with a hood so that it doesn't stink as much.
haha thanks, but no she is not long hair. I understand what you are saying though. Sometimes, if I had just cleaned the box and she uses it but doesn't cover, it stinks up the whole house so I just use the scooper and cover it myself and that helps alot. I always hope she'll catch on but I guess you can't teach and old cat new tricks either.
Is she by any chance a long haired cat? Long hairs are less likely to paw in litter to cover it up because the litter gets trapped in their paws. You could try a coarser type of litter that is less likely to get trapped in her paw pads, but if she has been not covering for 10 years, it is probably unlikely that she will start doing so now. As for cleaning and the smell, it probably wouldn't be any different if she covered it. I actually wish my cats were a little less diligent about digging in the little so there would be less little strewn outside the box and I wouldn't have to dig as deep to scoop it out.