I was labeled as “gifted” early on. I was also once tested for dyslexia/other reading disabilities, because I refused to pay attention in reading group. (I was just bored; at that point I was reading about six grade-levels ahead of myself).
I can’t agree enough with “let them do what they want.” Kids need variety and need fun, and while chess/violin/calculus/etc might be fun, it’s usually not something they can share with their peers. Throughout elementary school, I at some point pestered my parents that I wanted to do/play the following: soccer, softball, martial arts, acting, painting, writing, violin, horseback riding, girl scouts, swimming, pottery, and drums. With the exception of drums (which we simply couldn’t financially afford without giving up something else), my parents let me try everything on the list. Some things were great and I just kept going (eg, martial arts, writing, violin). Others, I lasted a season or two before losing interest (eg, softball). A couple things I went to one class, realized I sucked at it, and wanted to quit right away (eg, acting, painting, pottery).
Don’t let them quit just because something is hard. I think a lot of “smart kids” get used to school being so easy, they just coast through with minimal effort. Then when things get hard, they A) suffer serious academic consequences (as I did) and/or B) don’t want to bother. I don’t mean force them to keep doing it for years, but if they sign up for that acting class, they should tough the session out.
Granted, I’m not a parent, have no intentions to ever be a parent, and did in fact turn out mentally deranged, so you may want to take the above with a grain of salt.