Two of my kids are only 12, but I have kept my eyes on this issue because there are few natural opportunities for them to be challenged unless we actively seek them out. We have done this through talent searches, competitions and extracurriculars from about age 7. Nevertheless, the issue of limiting effort and other "self-sabotage" do crop up from time to time. I have at times allowed my kids to sabotage themselves rather than jump in to manage them so that we can autopsy the whole experience with an eye to avoiding it in the future, particularly when the stakes matter more. You seem to have articulated her thought processes quite well so I would just have some heart to heart conversations with her when you are both relaxed and open. This could be a relaxing lunch or other outing where you have each other's undivided attention. Sometimes kids need to hear what they are thinking/doing spelled out and the consequences emphasized.
