Hi Kori!
Since you will have your own car and are staying on site, I recommend driving to Downtown Disney and taking the bus to the Magic Kingdom. Since you have specific appointment times for
Bibbidi Bobbidi Boutique and
Pirates League, your best bet is for your DH/DS to take the bus from Port Orleans - French Quarter to Magic Kingdom. The buses begin departing from the resort to the parks an hour before the park opens and run continuously until about an hour after the park closes. Therefore, your DH/DS will have plenty of time to get to Magic Kingdom for their 9:00 a.m. reservation.
You can drive to Downtown Disney with your DD for your 9:30 a.m. appointment and then drive to the Magic Kingdom. You can meet up with your DH/DS and then drive back to your resort at the end of the day. Since you are staying on site, your parking will be free at all of the Walt Disney World resorts and parks. Your other option is to take a bus from POFQ to DTD and then a bus from DTD to MK, but since you are trying to get to a specific appointment time in the morning and you will be going to Magic Kingdom afterwards, I think driving is your best option.
The boat also begins departing from POFQ to DTD at 11:00 a.m. and then every 20 minutes until 4:00 p.m. and then every 10 minutes from 4:00 p.m. to 11:00 p.m. Since the bus doesn't depart until 11, this option won't work for you.
Please let me know if I can help you with anything else at all!
Magically,
Stacy