彼女はすぐ宿題を始めた。

she; her; her; girlfriend; sweetheart

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

immediately; at once; directly; soon; before long; shortly; easily; without difficulty; right (near); nearby; just (handy)

homework

indicates direct object of action; indicates subject of causative expression; indicates an area traversed; indicates time (period) over which action takes place; indicates point of departure or separation of action; indicates object of desire, like, hate, etc.

to start; to begin; to commence; to initiate; to originate; to open (e.g. a store); to start up; to establish (business. etc.); to start ...; to begin to ...