Summer78
Have you looked at our DLA guides on the Guides link at the top of the page?
You say you are aiming at the Higher Rate Care award. Be aware, HRC is awarded for substantial care needs during the day AND night, you only mention care needs overnight, no matter how severe the needs only the Medium Rate can be awarded in these circumstances. Does your child have care needs during the day as well?
Gordon
Nothing on this board constitutes legal advice - always consult a professional about specific problems