she always has a soft place to land at home.

You're correct that this might be situational, and she may self-regulate with time. She is likely going through normal hormonal changes associated with her growth spurt, and emotional swings can be part of this. However, mental illness (especially mood and anxiety disorders - the most common to begin at that age) is common, real, treatable, and no success in any activity can take precedence over our children's health. I've been there as a parent. Best of luck.