。
She gave birth to twins.
Literal
She [topic-は] twins [object-を] gave-birth-to.
産む ('to give birth to, bear') is the verb of choice for biological birth — both human babies and animal offspring. Japan tracks twin births in 双子手帳 (twin childcare booklets) and offers extra public support; rates of twin births rose noticeably with the spread of fertility treatments in the 2000s. 双子 ('twins') reads with 双 ('pair') giving the lucky/auspicious connotation that traditional Japan associated with paired things — though twins themselves were once viewed with mixed superstition. The simple structure here is a clean transitive: subject-object-verb with 産む taking 双子 directly as its object.