There may be support from Citizens Advice for DLA form filling or you can ask Contact, the charity for families of disabled children on freephone 0808 808 3555

More details here: https://www.citizensadvice.org.uk/benefits/sick-or-disabled-people-and-carers/disability-living-allowance/help-with-your-dla-claim/help-with-dla-form/

Filling in the form

Keeping a diary of your child’s care needs before you fill in the form can help when it comes to answering the questions. This way you’ll have recent examples of how you care for them, and a good idea of how long it takes you to do certain tasks like helping them get ready for school.