...does she define her emotions to you after a loss, either immediately or after taking some time for herself?
My kid takes losses hard immediately afterward and as long as I keep my mouth shut. After he takes some time to himself, he tends to define his emotions to me. Mostly, he says he hates to lose, even if he is the underdog (half of his matches in the 12s, he's 10). I dropped him a level, still 12s but not Open. He wins the tourney. No real elation, subdued reaction. I was pleased on both counts. He recognized his level and did not celebrate the mere victory and he was eager to go back up even if it meant more struggle.
Bottomline, emotions are tricky. If she continues to improve with a subdued outlook that could be fantastic. If you detect a disconnect or maybe a connect between her emotional caring and her improvement and performance or lack thereof, then it could be a factor to monitor to avoid burnout. Here is to hoping she finds the love to carry her through the journey.