What benefits can be claimed for terminal cancer?

Hi, my name is Rachael. I am a carer for my mum who has terminal cancer she is very mobile and is raising my niece who is 14. My mum is 67 and was self employed up until her diagnosis she is not good with paperwork that's where I come in I try and support her with red tape and mentally although what I think should happen with benefits and being in the know differs some what sometimes due to red tape I cannot help which annoys me I wondered if there is anyone who can help out there knowing exactly what she can claim. People within the government are very reluctant to give any help