。
She came to see us yesterday.
Literal
She [topic-は] yesterday us [with-に] meet [purpose-に] came.
会いに来た packs three pieces into a tight phrase: 会い (the masu-stem of 会う 'to meet'), purposive に ('in order to'), and 来た ('came'). The frame [verb-stem + に + motion verb] is one of the most productive ways Japanese expresses purpose-of-motion — 食べに行く ('go to eat'), 買いに来る ('come to buy'), 遊びに行く ('go to play/visit'). 我々 ('we') is the formal/literary first-person plural — speeches, official writing, and weighty masculine register; in everyday conversation 私たち would be the default. The choice signals a slightly elevated or self-important tone.