你好！她毕生致力于帮助穷人的翻译是She devoted her life to helping the poor。这儿的 to 是介词，不是动词不定式，所以后面应该跟名词或动名词等名词性词组（helping）。
说明很艰苦，勉强撑过去
She devoted her whole life to help the poor.
She devoted her life to helping the poor
