They really were the spitting image of each other.

Literal

Truly gourd-two [was-だった] [feminine-わ].

Built on the idiom 瓜二つ (lit. 'two halves of a gourd/melon'), meaning 'identical, exactly alike, spitting image' — the comparison is to a gourd cleanly split down the middle. The sentence-final わ here is the feminine plain-form emphatic particle, expressing a mild exclamation or assertion. Subject omitted.