Just wanted to chime in about science olympiad tryouts; i haven't read the whole thread, but agree with Indigo avove. It would also help to get some inside info about your school's team- teams vary quite a bit. Our DD was also put off by the idea of tryouts, but after much coaxing and a personal shove from a beloved teacher, she ended up attending. She knew early on in the tryout process (it lasts several weeks here) that the team would be a good fit and that she wanted to be on it. The SO experience has been a defining one of her middle school years- she found a tight-knit, supportive peer group, encouraging teachers/coaches who understood her, and limitless opportunity for intellectual challenge. Her confidence has soared, and she has explored in depth many areas of science not typically touched on in middle school (often using AP and college texts, lots of independent research, etc).
Just be aware that some teams are quite competetive, even between the team members (depends on how the team is organized/coached, and whether they have to compete amongst themselves after joining the team. Here, all the competition is in making the team; once you are on it it is completely collaborative, but they dont all work this way). The SO website is a good introduction, but you really want to know how the specific team functions before choosing to encourage your DD. Also, be aware that SO can involve a significant time comittment, again, depending on how the team is structured. For DD this was a positive, as she would probably be reading about/doing science much of the time anyway, but it does limit other extracurricular opportunities.
Best of luck to your DD!
