After just a few days in a coma, the muscle tissue starts to deteriorate rapidly. It doesn't take long before the muscle mass deteriorates to the point that gripping and standing on your own is impossible. Stephanie would not be able to walk after 20 years in a coma.
After more than about six weeks in a coma. most patients have severe brain damage. After 20 years year Stephanie would most likely be completely brain-dead from oxygen deprivation.
The graduates are randomly announced without any order.
During the graduation ceremony, instead of the students being in order, students are called one at a time.
The Maryland license plates in the present day have a wrong serial format, 1AB23D4, when it should be 1AB2345.
The yearbook shows Stephie's DOB to be Feb 2 1984, and that she went into the coma on May 20 2002. So she would have been 18, not 17, then, and 38 not 37 when she wakes up in April 2022 (Martha says there's a month of the school year left, and Stephie confirms that that's the amount of time she missed).
Stephanie put a video of her dance routine to the song "A Moment Like This" by Kelly Clarkson in the school archive before going into a coma. She was in the Senior Class of 2002. "A Moment Like This" was released in September 2002, when the Senior Class of 2003 school year was just starting. The Senior Class of 2002 would have graduated months before that song was released.
For the cheer routine the songs "Come On Over Baby" by Christina Aguilera and "Hot in Here" by Nelly were released in 2000 and 2002, respectively.
Seth says that he's taking a Lyft to prom, but he drives Martha to the lake house during the after-party.