Thank you for your answer, albeit disappointing, it is as I expected. During the time that I was working on these projects, my wife acted as typist, telephone message taker when I was out, cleaner of my office, provider of cups of tea etc.
Now that the projects are completed and the royalties starting to flow, apart from the possible tax advantages, I thought it would be nice to give her a share of the income.
Despite the disappointment I shall rate your answer at the highest level
But as she was clearly acting and making a contribution to the business then you are in a far stronger position to claim that a proportion of your royalty income is attributable to her efforts in exactly the way rental income could be split. I submit that with this new information your position is strengthened.
Please be so kind as to rate me before you leave the Just Answer site.