I often worry she may rebel and go too far. (Para. 22)
Meaning: I often worry she may fight against or reject my control and do something that goes beyond limits.
Note: "go too far" is an idiomatic expression which in this context specifically refers to "getting pregnant, doing drugs, getting drunk, committing crimes, or being promiscuous and getting AIDS or VD".
go too far: do or say something that goes beyond accepted our accepted limits
I know you are radical in your thinking, but don't go too far. 我知道你思想激进，但不要走得太远。