、。
She expressed her thanks for his helpful advice.
Literal
She [topic-は] his [genitive-の] beneficial advice [toward-に対して], gratitude [genitive-の] words [object-を] expressed.
Three formal-register elements stack here. ~に対して ('toward, with respect to, against') is a more formal alternative to plain に when marking the target of an action or attitude. 感謝の言葉 ('words of gratitude') is a set noun phrase — saying 'expressed words of gratitude' is more refined than just 'said thanks.' 述べる ('to state, express') is a formal speech verb (compare casual 言う). Together: a stiff, ceremonial way to say 'she thanked him.'