Many factors obviously contribute to ACL tears, perhaps the most important (other than genetics) being muscle fatigue. The number of minutes played in a single game has a high correlation to ACL injury risk. Here's a link to an interesting article.
https://fitforfutbol.com/2016/02/th...y-and-sleep-on-performance-injury-likelihood/.
As discussed above, there are many ways a girl can take steps to potentially reduce the risk of an ACL injury. First, if you have a family history of knee problems, don't play soccer. Second, cross-train, build leg muscle strength and learn the biomechanics of running properly to avoid excessive knee strain. Third, don't play DA or for the GNT. There is no legitimate reason a 15-16 year old girl should play a 90 minute game, let alone train 4 days a week and then play 2 90 minute games over the weekend. Is it any surprise that the U17 WNT has lost at least 5 players to ACL tears in the last year? Finally, put your daughter on the pill.