。
She was kind enough to help us.
Literal
She [topic-は] kindly [emphasis-も] us [object-を] helped-for-us.
私たち (わたしたち, 'we/us') extends the benefactive action to a group. The くれました ending is the polite past form — appropriate when relating the story in formal or semi-formal contexts. In the giving/receiving verb system, くれる is always used when the action flows toward the speaker or the speaker's group, regardless of group size.