The feeling that came over me after watching the hourlong documentary Shadya (part of PBS’s Independent Lens series airing next Tuesday) was one of gathering worry. Fresh-faced, ebullient Shadya Zoabi is an Israeli Arab girl of 17 with a gift for karate — she’s a world champion, in fact — and yet the most fearsome opponent she will face as she gets older isn’t some black-clad ninja out of a Bruce Lee flick but the forces of female suppression in her male-centered Muslim society. Her proud father is intensely supportive of her desire to keep at karate, but her strict older brother looks angrily agitated at the mere thought of his sister showing off any bodily abilities. Her younger sister studies karate as well — and they obviously bond over it — but tut-tuts when Shadya refuses to take the time to pray or dismisses other aspects of the religion. And while Shadya is engaged to a smiling, hulking young man from another village who beams at the thought of his soon-to-be wife bringing home more trophies, you wonder whether this is all progressive lip service for a documentary crew. The answer is revealed, since the film covers a two-year period in which Shadya gets married and comes to grips with the preordained responsibilities of her culture, and there are some surprising (and sad) family reappraisals along with the expected nonwaverers. But mostly you’ll watch this once-petulant, now-domesticated young woman carefully balancing a tray of drinks she has to bring to her husband and his guests, and wonder if this was the intended result of being so talented at a meditative, spiritually centering sport.