I'd have a chat with the CCCS - consumer credit counselling service.
http://www.cccs.co.uk/
Stay away from anybody else that offers to "help" you with your debts. The vast majority want to provide the same sort of options that CCCS do, but for a fee or taking a cut of your monthly payments.
Dont believe the adverts that offer to wipe them out etc.. most are a con.
The CCCS service is free and very usefull. Give them a ring and discuss your problems with them, they will steer you in the right direction better than any of us can (assuming your unlikely to divulge all personal finances on here)
They could recommend something like a DMP - Debt management plan. CCCS will come up with a budget for your mum, detailing all her expenses and outgoings, and want proof of her incommings. They work out what she can afford then negotiate a better rate of interest with the bank on her behalf. You can try this on your own, but not all lenders will be co-operative with this approach unless she's talked to somebody like the CCCS.
What happens is that CCCS work out what she can afford, then take a payment each month for that ammount, and distribute it to her creditors. During this time access to the CC will be suspended.
Bankruptcy is very much a last resort and can wreck your credit for years after. DMP is much better as then your Credit Record at least shows you making payments, even if not the full one.
DMPs are usually offered to people with more than 10k of debt to more than 5 creditors however, so will probably not fit your mothers circumstances if one 7.4 grand card is all she has. Anyway CCCS will steer you in the right direction.