Dealing with Debt

Hello, My mum got diagnosed with stage 4 breast cancer (treatable but not curable) in May. She has been on full sick pay for 6 months which is coming to an end in October. She is still waiting for PIP to be approved. She is worried about her £4000 credit card/catalogue debt. Is there anything we can do to help? I am currently on maternity leave with no pay so cant help financially but want to look to see what help is out there. Thank you in advance