I personally don't have a problem with the 'permission' bit. Whatever works for you two is what works.
As someone who was denied getting a job many years ago, I will say that denying someone that can be dangerous. It eventually led to the downfall of my marriage.
The cirumstances were kind of similiar; it wasn't necessary for me to work, and we had no children at the time. But it can put someone in a...funny...space to not having anything they can truly call their own. Not money, not sense of self, not the roof over their head.
You seem to be a guy like my ex who would say that everything you have is hers. But if she doesn't feel that...
if she doesn't feel a sense of purpose and have the mental...dignity? (I can't think of the word I want), then what you saying it is hers doesn't matter at all.
I'd let her, where I you. Or, if not, as Timbo said, she may eventually do it anyway.
