。
She tried to grab his hat.
Literal
She [topic-は] his [genitive-の] hat [object-を] tried-to-take.
Volitional 取ろう + とした gives the 'try to / attempt to' reading via the ~ようとする pattern. The past form ~ようとした often (though not always) implies the attempt was unsuccessful or interrupted, depending on context. 取る is a wide-domain verb covering 'take, grab, pick up, remove' — context (here a hat) narrows it to grabbing.