One of my children is a Division I athlete and unfortunately was injured. That is when the nuances of a medical redshirt was explained to us. First, we were told there is no such thing as a medical redshirt. There is a Hardship Wavier under Article 14 of NCAA Division I Manual.
Whoever in the thread said that the athlete's participation in the sport must be 30% or less is correct with the condition that in some sports it is three contests or 30% whichever is greater.
In the last year of their career the athlete and the institution apply for a "Hardship Waiver" to obtain another year of eligibility. (Article 14.2.4 of the NCAA Division I Manual)
So, if Morgan indeed played thirty percent or less of the schedule this year then she is eligible to apply for a Hardship Waiver in the final year of her career. Nothing is done now other than be sure the proper documentation is there to be used to support the request for Hardship Waiver when they make that request.
On many occasions, schools will apply for the hardship waiver sooner than that. The NCAA will look at the documentation whenever it is submitted and approve an additional year if warranted.
BTW, although the term "redshirt" is so often used in lieu of "medical hardship waiver", the term "redshirt" is never used in the NCAA bylaws with the exception of an "academic redshirt", which is a player who must sit out the first year due to his/her H.S. GPA but who does not necessarily lose a year of eligibility.
All players automatically are given five years to play four years of their sport. If a player or his/her coaches decide to sit out a year - whether it is due to an offseason injury or a mandatory sit-out year due to a transfer or a desire to push back participation to a later year to get better (or have a better chance to play) or for academic reasons etc - there is no need to petition the NCAA. Eligibility to play in his/her fifth year is automatic if the athlete has not already played all of the first four years. This was the situation that Heather Buck and others - including many football players - were in. Although the NCAA bylaws don't call this a redshirt, this is what is commonly called a redshirt. The only need to go to the NCAA to get another year of eligibility is if there was an early season-ending injury and you want to play a fifth year OR if a player wants to play in a sixth season due to two years of injury.