。
She made the most of the opportunity.
Literal
She [topic-は] opportunity [object-を] fully made-use-of.
機会 ('opportunity, chance') is the formal partner to the more colloquial チャンス. 利用する ('to use, to make use of, to take advantage of') is broader than just 'use' — it covers exploiting opportunities, riding circumstances, even using systems and infrastructure. 十分に ('fully, sufficiently') is the standard adverb for 'to the maximum extent.' The combination 機会を十分に利用する is a stable, slightly formal register collocation — at home in a job interview or news article, less in everyday chatter.