In addition to me, a qualified instructor is insured to fly it and has had conversion training.
My wife is training for her PPL.
Can the instructor give her any training in my permit aircraft - accepting that this time may not be counted towards her PPl and that he may not be paid for it?
I think you will find that "sole ownership" includes immediate family members (i.e. Wife, sons and daughters) so your wife could actually receive instruction that counts and the instructor can be paid.