I have moved in with my partner and am renting my own property out. The rental income I wish to share with my patner and want to transfer half of the proceeds to her. Will she be required to pay tax on this amount ?
If you are giving her half the rent on which you have paid (or will pay) tax yourself then no.
If you are giving her half the property, so that she gets half the rent from it, then yes - subject of course to any valid deductions, allowances, etc.