There is no legal way that they can prevent this provided it is just a personal relationship and there is no element of the work which the reader does, being done whether for free or for payment, for you.
If that was the case, and there is a restrictive covenant in the employee’s contract, they can get an injunction, not to stop the contact but to stop the work or advice element between you whether you are paying for that service or not. Extremely difficult to enforce but nonetheless, they could make it awkward for the employee.
Does that answer the question? Can I answer any specific points arising from this?
Please don’t forget to use the rating service to rape my answer positively. If you don’t use the rating service, I don’t get paid.
You may think that the thread closes after rating, but it does not, it remains open, and we can still exchange emails if anything needs clarification.