As I stated in my earlier post my primary concern in your original post centres around the long drive to get to school. I don't believe it is in a child's best interests to have such long travelling time on the way to school. Especially in the first year of school as kids seem to be so very tired anyway for the first term or two until they have adjusted to attending school.
The other issues of laundry, uniforms, bags, wake time are non issues to me and as others have stated are your DH's responsibility anyway.
If your DH and his ex agree that the travel time is acceptable, then he needs to step up at your end and ensure your SDD's needs are met.
One thing to consider is that she will be quite displaced any way with the arrival of the new baby and if time with you is reduced around the time the baby is born, she may think the baby is replacing her, or her father doesn't like her anymore.