I had to write on the census form that I had spent part of my week looking after a child with a disability. Bob's form said that he couldn't do some things that a normal child his age could. I kept ringing the helpline saying "is it normal for a 3 year old to be able to eat a banana without going to A&E, does that count?"
The more you write, the more they may be able to help, not just with your dd, but with getting more funding from the powers that be for the DLA generally.