Your concern is justified.Sometimes too much of anything can be the wrong thing for you in the long run.
However,these young ladies are in much better shape than the average young lady,and as part of the process to achieve to become better at their game,extra activities in their expertise is important in some ways,to their growth as a player and person.
Even the most careful player in any sport can become injured,because of the repeated use of muscles,and in some cases,the abnormal use of the muscles due to falls,poor positioning,body contact,etc.
With Morgan and KML,this just happens to be a year where the right place and the right time happened for injury.
I am very confident,that if the coaching staff,and especially the training staff,thought that Morgan couldn't go this year without repeating injury,and that KML wasn't good to go,in their professional thoughts,both girls would have not started or continued in the games.
My hope is that Morgan gets a full recovery and is able to resume the things she holds dear to her,with no limitations.
My hope is KML gets through this setback completely healthy and renewed with the energy she has always displayed in the thing she loves to do.