Sit down with your daughter and make a budget, detailing her earnings, how much she pays in Income tax and all her expenditure. And I mean ALL - if she doesn't already do so, she needs to keep all supermarket chits for a month, so she knows how much food, toiletries etc. she needs for a month.
Then make a list of all her debts. ´Get her to phone her bank and ask for an appointment with an advisor and go with her to that appointment. She need to get the bank to help her work out how she can get out of debt. Usually, a bank employee who phones on her account to a credit card company or other creditors can get a better scheme in place than she will be able to.
Depending on how much debt she is in, it may take a long time to clear it, but the sooner she starts the sooner she will be out of debt. If possible, try to get the creditors to allow her to pay off part of the interest and part of the principal simultaneously, as that way the compound interest will decrease as the principal decreases.
I believe some charities have financial advisors too, if your daughter can't afford to pay for a chartered accountant's advice.
I hope you and she manage to find a solution to the financial difficulties.
You don't mention whether you could afford to help her, but if you can and will, please find a way of drawing up some legal agreement with her, otherwise her benefits may be reduced.