Its never a good idea to add to debt in this sort of situation. Apart from anything else, if she does so knowing she can't really repay it she could find herself accused of fraud. If she can't come to an agrrement herself she could ask for help from a local CAB, or CCCS or Payplan. None charge anything. Do not go to a fee charging debt management company.
If her only income is state pension has she checked whether she is entitled to any benefits, such as Pension Credit, Council Tax Benefit or (if she rents) Housing Benefit? CAB could help her with this.