An introverted teen with special powers seeks to avenge her family's killers and rescue others like her from slavery.
There is a means, sort of: her “special powers”. What those “special powers” are that enables her to achieve her goal ought to be more specific.
And there should be one primary goal. For the purposes of the logline, either her primary goal is to avenge her killers or rescue others. (In the story proper, one may be entailed in the other; even so, there should be clearly designated primary goal. )