Ironically it all seems much easier visiting the UK as a partner of a non-UK EU National.
My wife is also not a native UK national but we never tried a visit visa, Mrs LoM came to the UK on a (bone fide) student visa and we married before it expired. Apart from a little moderate pain from UK Immigration (I am not sure they are different from any public sector body with a degree of power in that respect) we had no issues.
If you have your own business it may be that she would need to visit the UK for business reasons
which may attract slightly less scrutiny but YMMV.