If you need more hours than the regional center offers, you have to explain why. Write out your weekly schedule and bring it to an IPP meeting. Include all the activities of your personal lives and the time you spend caring for your child. Note the time that is left over.
You can ask for respite for errands, activities with your other children, church, or free time. List the behaviors or medical needs (and their frequency and how much time they involve) that your child has that require your full attention. List your own needs.