Hello, I am Keith, one of the experts on Just Answer, and pleased to be able to help you with your question.
Until you get your wife's name on the deeds as a Joint Tenant then you are in a cleft stick. Once you have done this % of the rental income would be part of her income for tax purposes and she would have her allowance, currently 11K to offset this. [line 1 should read 50%]
Ido hope that my reply has been of some assistance.
Thank you for your support.