。
She is blessed with good sons.
Literal
[topic-は] good sons [with-に] is-blessed.
~に恵まれる ('be blessed with') is a passive-form set phrase — 恵まれる is the passive of 恵む ('to bestow, give blessings to'), and the thing one is blessed with is marked with に. This passive marks the speaker as a beneficial recipient of fate or fortune. Common collocations include 才能に恵まれる ('blessed with talent'), 環境に恵まれる ('blessed with circumstances'). Note: 息子たち ('sons') uses the plural marker たち — Japanese plural marking is generally optional and used here to specify multiple sons.