。
She won first prize at the exhibition.
Literal
She [topic-は] exhibition [at-で] first-prize [object-を] obtained.
展覧会 ('exhibition') is a common Sino-Japanese compound for art shows, gallery exhibitions, and similar events. 一等賞 ('first prize') combines 一等 (first class/rank) and 賞 (prize). 得る ('to obtain/gain') is slightly more formal than もらう for receiving an award.