Welcome to the Disney Parks Moms Panel Tish ~
I love the special events at the Magic Kingdom (MK) and Mickey's Very Merry Christmas Party (MVMCP) is incredibly awesome!
Guests can utilize their Disability Service Access Card (DAS) for attractions at MVMCP. As far as meet and greet locations, there have been times that we have been able to get return times but not at others. Typically, we have been given return times at character meet and greet locations that are in a permanent venue like Town Square Theater. I'll be honest, I have found it to be a little inconsistent at the locations out in the open - some Cast Members were willing to give DAS return times and others were not. It is harder for them to do that in those settings. I did find that the nicer we were about it, the more success we had trying. In some locations they did not give us a DAS return time, but typically at least let one of us walk around with our son while the others in our party waited in line.
I know this does not give you a definite answer regarding the meet and greet locations as they seem to be a gray area, especially during MVMCP. It may help to bring things to entertain your daughter while waiting in line (favorite toys, electronics, head phones, etc.). I also try to keep my son engaged by talking to him or playing little games while we wait in line. It doesn't always work and sometimes we just have to take a deep breath and regroup.
Guests attending MVMCP can enter the MK beginning at 4 p.m. If you make it to the MK around 4 p.m., I would head straight to a Disney FastPass+ service (FP+) kiosk to see if any FP+ selections are available prior to the start of MVMCP at 7 p.m. that evening.
Here is some
information regarding the DAS and children with autism that may assist you.
Wishing you minnie magical memories :-) Allison V.