Sorry to hear about the family you are assisting that is having financial difficulty. There are many charities in the UK that can help as what I have done is to look for those that have a good record of assistance and can assist as soon as possible. Some for you to inquire with include:
1. Turn2US is a service that assists with financial difficulties specifically. They offer assistance with grants as well as financial support to families such as the one you are trying to assist:
Grants are available for those in financial need. The same site offers assistance with this:
2. Grants help with paying bills:
3. GuidestarUK is a wealth of information as they catalog many of the charities found in the UK. You can then search by financial need for example to find one that can be the best help for your family in need:
I hope that this information was found useful as please inform me of any additional questions/concerns you have. Also if you could take a second to rate my assistance so that I know my help was found useful today.