
Unless it is a breed that spaying affects teh coat in anegatice way as regards shwoing (thinking silky coated breeds and Spaniels here( then there is no reason you can't spay ehr and still show.
It is many years now that the Kennel club changed the rule that stated only neutered stock with registered progeny could be shown. Now all you need do is inform them that it has been done and show as normal.