。
She didn't utter a single word of encouragement.
Literal
She [topic-は] encouragement [possessive-の] words [contrast-は] one-word [even-も] did-not-utter.
A contrastive は after 励ましの言葉 foregrounds encouragement as something she specifically withheld — implying she may have said other things. 一言も...ない ('not even one word') is an emphatic negative pattern. 発する (はっする, 'to utter, emit') is more formal/literary than 言う.