Is your mother getting Attendance Allowance, because she should be and if so, you could then apply to the council for a 25% reduction of the council tax, based on your mother's "severe mental incapacity" (horrible phrase but that's what it's called) - assuming it is just you and her living in the house.
You are going to talk to the CAB? You may be eligible for a loan or grant. Also, I assume your mother receives a pension? If so you can apply to be a appointee and have her state pension and any other benefits paid into your account.
From www.dwp.gov.uk/docs/third-party-access.pdf
You are going to talk to the CAB? You may be eligible for a loan or grant. Also, I assume your mother receives a pension? If so you can apply to be a appointee and have her state pension and any other benefits paid into your account.
Customers Incapable of Managing Their Own Affairs
Appointees
A customer may require someone to collect or receive payments on their behalf
because they are no longer capable of managing their own affairs. This may be
at their request or an arrangement that is made for them.
A DWP officer acting on behalf of the Secretary of State can authorise someone
else to act on a customer’s behalf if the customer is incapable of managing their
benefit. This is called an appointment to act and the person or organisation
appointed to act is called an appointee. A social security appointee is not
appointed to look after the person's affairs generally, only to deal with the
person's benefit/pension entitlement and payments.
Appointee action should only be considered if a customer is incapable of
managing their own affairs even if they require some support to do this, e.g. due
to their mental health or physical disability. Appointee action is not appropriate
for customers who are capable of dealing with their own affairs.
Points to consider
The account into which benefits and pensions are paid should be in the
appointee’s name only. An appointee cannot use a joint or someone else’s
account. With a joint account, both account holders need to take equal
responsibility for the operation of that account. This cannot happen where one
party is incapable of understanding what is happening with the account.
From www.dwp.gov.uk/docs/third-party-access.pdf