What cattery software do you have, if any? Just about all can make a pedigree..but there's an online free website I knew of that you could do it with also.
But if you don't, you probably DO have the pedigrees on your cats and could send copies of both parents to a prospective buyer, right?
I do think that a buyer has a right to know the background of a cat they wish to purchase. Many don't care, but if they ask I believe a breeder should be able to give them that information.
Now, I know you only have one queen...but when purchasing a stud, wouldn't you wish to know ahead of purchasing him if there was significant relatedness between him and your queen? I actually HAVE had people that were set on buying a kitten from me when I asked them what cats they were intending to breed him to and have to tell them how related they were. One breeder had signed a contract and sent me the holding fee for one male then posted online another male she just had delivered and he was my kitten's uncle! My kitten's mother was the full sibling of that cat. She hadn't checked pedigrees at all...even though I had sent her my kitten's pedigree.