Help! What do I pack

So I'm flying with my soon to be 8 month daughter on untied airlines. From Texas to Utah. We have to go to the airport at 8 am. Our flight is not until 2:30 pm, we have to go early because we are moving my husband is driving the moving truck with our son. So they need an early start....

The diaper bag I can pack for her will not count as a carry on nor will her stroller. Her stroller I can gate check for free according to the website. her pack n play i can check as one of my bags. I will get a personal bag I think. I have to call and find out.

My question is what would I pack for that long in an airport? She will be flying on my lap.