Hi Marisa, and welcome to planDisney!
Disability Access Service (DAS) is a fantastic benefit for those guests who have difficulty tolerating extended waits in a conventional queue environment due to a disability.
As an eligible guest, you can pre-register your daughter via the
virtual live video chat 30 to 2 days prior to your scheduled theme park visit. Once approved, you will use the DAS Advance planning option to reserve up to 2 one-hour return windows for each day of your planned theme park visits. Once those select experiences have been redeemed, you will then be able to utilize the Disability Access Service via your My Disney Experience app to reserve additional select attractions once your previous selection is redeemed.
I do not believe that it will make a difference when you complete the pre-registration process as long as you are within your 30 to 2-day window. Also, be prepared to wait when you pre-register in case the wait times are lengthy.
Please let us know if you have additional questions.
Have a magical
Walt Disney World Resort vacation!
Raquel