There are a number of grant awarding organisations that provide funding for children with disabilities. For most grants the child/young person would need to be in receipt of DLA or PIP. Families often have to give detailed financial information about income and outgoings.
Please contact Skills for People for more information.
There are organisations which will help with funding for holidays or have reduced cost holiday accommodation available for families who have a child with a disability.
Skills for People have an Holiday Information Booklet with more details.