。
She devoted her whole life to that work.
Literal
She [topic-は] that work [target-に] life [object-を] dedicated.
一生を捧げる ('dedicate one's life') is a fixed phrase for absolute lifelong devotion — 一生 ('one lifetime, the whole of one's life') + 捧げる ('to offer, dedicate, devote'). The に marks the recipient/target of the dedication. 捧げる has religious or ritual undertones (offering on an altar), giving the phrase a solemn, reverent feel — used for callings, causes, art forms, or another person to whom one's life was given.