surely, if she was the partner, the more pressing issue would be her income hasnt been taken into into account?
Were the DWP treating as a couple and including her income?
Even if they were a couple, it mayy be that they couldn’t share a room, or needed an occasional overnight carer, in which case the (2) bed room you have used would still be correct.
Any O/p you do discover will need to be sent to the exors of and recovered from the deceased estate, assuming they have anything but as passported benefit in payment, presumably quite limited capital/assets
