An hour and a half sounds like more than enough time to me - I wouldn't lenghten that. Does she have a good morning routine? Here it's potty, breakfast, brush teeth, get dressed, brush hair, out the door. It takes about 30 minutes, though my husband drops her off on his way to work so I just have to get her ready and not myself.
9 hours doesn't seem like much sleep to me for a 3 year old (unless she takes a 3 hour nap?). Maybe she's too tired to eat when she gets up? Just a thought.
Otherwise, I agree with your husband. If she's hungry, she'll eat. Does she drink milk? I'd offer her some whole milk or a smoothie in the morning to fill her tummy up a bit.