As she doesnt have any papers on her possibly breed, she is DLH, and thus - you will show her in the domestic class. Adult domestic "moggies" MUST be spayed for showing them. The only moggies at the show not neutered are kittens.
IF you would suddenly find her papers somewhere making evidence she is pure bred Norwegian (talking hypothetically) you can still show her in neutered class. It is true, it may be said the biggest prestige is in the fertile classes - but they DO have neutered classes too.
So, in our main variation: neutering is a must. In our hypothetical variation: neutering is entirely feasible.
One thing more. At least in Sweden, you must belong to a cat-club if you want to participate in shows. Perhaps it is so in your country too. But it is no real drawback. Most clubs do accept members with moggies too, are even happy with it. And thus - you can almost surely get much advices and even help with arranging of your participation and how to do the practical details.
And you do meet lotsa of cat interested people, most of them are kind and friendly to newcomers.
They may be sour to konkurrents - it happens - but not to newcomers.
Welcome into the gang!
