。
She just finished washing the dishes.
Literal
She [topic-は] just plates [object-を] [finished-washing-洗い終わりました].
洗い終わる ('finish washing') is a compound verb stitching 洗う ('wash') with the auxiliary ~終わる ('finish doing'). The pattern is highly productive: 食べ終わる ('finish eating'), 読み終わる ('finish reading'), 書き終わる ('finish writing'). Distinct from ~終える, which is its transitive partner — 終わる is intransitive 'come to an end,' 終える is transitive 'bring to an end' — though both can attach to verb stems with similar meanings. ちょうど here pinpoints the moment of completion: just now, just finished.