Gadabout Gran: Being dyslexic doesn't mean he isn't also lazy - people can be both, without these necessarily being linked, or either one without the other. If he hasn't got an official diagnosis and support, then I suppose it comes to much the same thing from the OP's point of view: she has to make sense of a chaotic bundle of papers.
This work isn't all profit - the assistant/bookkeeper may also have to pay tax and NI, and supply materials such as a storage and work space, print cartridges, stationery etc. This needs to be factored in to the hourly rate.
Searching for recipe in Supercook magazine