“who played in a soccer game the day before she was found unresponsive at her father’s Randolph home on Feb. 22.”
Hopefully the mother realizes that the police aren’t going to investigate what appears to be a medical anomaly, so she’d better do it herself. An injury at this game is the best/only clue in the article.
The mother might want to ask the coach, other players, spectators, et al who were at the game whether her daughter had any collisions or hard falls, got knocked down or kicked in the head, headered the ball, etc. Seek video. If anything like that happened, make sure the medical examiner knows about it before the world’s slowest-to-schedule autopsy.
Mother might want to see if her child got any covid shots.