Hi Rebecca
If you have been given an extension then the claim will be paid from the date on the form.
You can only send in what you have, if appointments have been cancelled then send in the cancellation letters, this shows that through no fault of your own appointments have been cancelled.
You can always write a supporting document as to what help and support you give to the child, if you have family members who also provide support, they to can write a supporting document, it all adds weight to your claim.
Check out our new child DLA Claim guide to see if they meets the criteria for an award.
www.benefitsandwork.co.uk/help-for-claimants/dla/#dlaclaims Gary