。
She's so studious and smart that she can get a scholarship.
Literal
She [topic-は] scholarship [subject-が] obtainable [to the extent-ほど] serious [and-で] head [also-も] good.
The ほど clause sets the degree — she's serious to the extent that a scholarship is obtainable. 得られる is the potential form of 得る (to obtain), so the whole degree clause means 'to the degree that getting a scholarship is possible.' まじめで connects two qualities using the te-form of the na-adjective: serious and (also) smart. 頭がいい (literally 'head is good') is the standard colloquial expression for 'smart' or 'clever.'