Don't know what age your player is, but did she talking directly with her coach during the period where her playing minutes decreased? Did she enjoy playing with the team and for he coach?
Most important for the player is too continue to develop the love of the game. Coaches who help players learn to love the game are the ones to look for so players will continue to stive to get better and be involved.
Separate the team from the player because at the ulittle ages kids need to learn how to play for themselves not just the team. During the games or training they can be happy or not with their efforts and usually know the things they need to work on. The big question is will they work on those things and will the coach(s) help them? development is up to the individual.
Sometimes playing on a top team is not the best fit for a player, they rely on teammates too much and don't push themselves enough to keep getting better individually. Nothing really can take the place of work rate or effort and a change can be motivation to do so.
Development is getting better or improving at something. Not everybody develops at the same rate and there can be some stop, go, regression, progression, etc.
We need to learn new things and change to keep developing. Playing for the same coach or with the same players is comfortable but change can be good every once in a while