Also, your return time will be about three hours before your flight - in your case, that means about 12:45-1:00.
You need to be at the DME pickup location with all your luggage and your entire party, fifteen minutes before your assigned time.
If you left luggage with Bell Services, you need to allow at least fifteen minutes to reclaim it.
So you need to be back at CSR between 12:15 and 12:30.
You need to allow a good 45 minutes to get from one resort to another using Disney transportation. Longer is better, but you could probably manage that time frame from the GF to CSR, via monorail and bus.
So you'd need to be on the monorail platform by 11:30, maybe 11:45 if you're willing to push things a little.
Even if you'd change your plans to breakfast, you probably don't want a reservation that starts much later than 9 AM.
Remember, if you miss your assigned Magical Express bus, Disney is not obligated to find you room on a later bus. There will be other Guests assigned to the later-departing buses; or, if there aren't, there won't be a well-timed bus departing your resort, period.
Say your pickup time is 1 PM. You miss that and expect to get on the 1:30 bus - but there are no Guests whose flights required a 1:30 pickup at CSR, so, no bus - so no ride.