Small Biz Secondary Income - Hiring Family Member as Freelance

Arfa__

In my primary work I am a higher rate tax payer, hitting the 40% bracket. I also have secondary income from a small web blogging business. The income from which I declare through the standard self assessment process. This extra income is fairly small, but I'm still paying 40% tax on it obviously.

My wife now wishes to contribute and help with this secondary blogging business. She is currently house wife (kids under 12 in house) and only works a handful of agency teaching shifts on occasion - crucially earning nowhere near her tax free allowance.

As such, I would like to employ my wife in this secondary business and utilise her as yet unused tax free allowance. What is the simplest and easiest method to do this? I'd rather not getting involved in lots of faff of PAYE, paying her NI etc.

Would it be feasible to hire her as a freelance? i.e. let her invoice the business for specific editorial commissions etc - and then simple write this off as a business expense. I guess it would be up to her to file her own self assessment (a must? or only if she got anywhere near tax free allowance?); and manage her own NI payments (though in theory not required due to kids under 12, recipient of child benefit - yes?)

Doable? Thoughts? Tips?