I find this whole thing both sad and amusing at the same time.
It is ridiculous that video was shot and circulated of U14 girls playing a soccer game, presumably by someone who wants to make sure that the 13 year-old GK is publicly disgraced for being overly aggressive with their little princess(es).
It is a ridiculous overreaction to claim that the girl who was fouled was "almost paralyzed" because she wound up on the ground. By that standard, anyone who has ever been tackled in an American football game, fallen off of a bicycle, or slipped on an icy sidewalk has been "almost paralyzed". Yep, that seems like a logical conclusion.
Apparently, the offending GK was given a straight red for her effort, as she should have been. Most likely, league rules will state that she is suspended for the next match. If the behavior is repeated, any subsequent suspensions should be longer. It is up to the referee(s) and the league to enforce the appropriate sanctions. This is where it should end. Not with parents, not with videos, not with lawyers, not with public shaming.
Soccer is a physical game - sometimes excessively so, but that is why there are laws/rules that govern the way that excessive behavior is handled. There is contact. Players often are taken to the ground by opposition. If this is not acceptable to you or your child, there are a multitude of other competitive sports that entail little or no contact whatsoever. No one is forcing anyone else to participate in soccer, and no coach, referee, or league is "intentionally putting kids in harm's way". Seriously, do you hear yourself? Like a referee or coach wakes up in the morning on a mission to make sure as many kids maim each other as possible.
Finally, while I don't necessarily condone this, if all else fails, there are methods that can be employed by a player (or players) during a match to "motivate" a dirty opponent to change his/her approach. Let's just say that a player who takes a cheap shot on me or my teammate should not be looking forward to seeing us again later in the season.