I can't see why the DWP would remove a Carers Allowance as long as you both continue to provide 35 hours of care a week to whoever is the caree.
As long as your claims continue to be separate from each other I can't see any changes being necessary, with the possible exception of any Severe Disability Premiums that are being paid, which you should retain as long as you are classed as renter and rentee.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems
