teresa
I am afraid that I am not aware of any direct help in this area.
I am afraid that Winter Fuel Payments are only available to pensioners, there is a Cold Weather Payment but this is only triggered when the temperature is at or below zero for 7 consecutive days.
Certain Income Related benefits may entitle a householder to a reduction in their electricity payments, but I doubt your daughter will qualify as she is not the person paying the bill, you need to speak to your energy supplier about it, it comes under the Warm Home Discount scheme.
If your daughter is still receiving DLA Medium Rate Care then you or your husband could claim Carers Allowance for her providing that you were able to commit to providing 35 hours of care a week (there are other restrictions).
If any of the members have any ideas then please feel free to add to the topic.
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems