。
She gave me good advice.
Literal
She [topic-は] me [to-に] good advice [object-を] did [for-me-くれた].
忠告 ('advice, warning') is a Sino-Japanese noun built on 忠 ('loyalty, faithfulness') + 告 ('inform, announce') — etymologically 'an honest informing,' carrying a slight weight of seriousness or earnestness compared to the more casual アドバイス or 助言. 忠告をする ('to give advice') is the standard verbal form. Combined with 良い ('good') and ~てくれた (benefactive), the sentence conveys appreciation for advice that the speaker found valuable.