She was blessed with both intelligence and beauty from birth.
Literal
She [topic-は] innately intelligence [and-と] beauty [with-に] was-blessed.
生まれながらに means 'from birth, inherently.' ~に恵まれる (めぐまれる) means 'to be blessed with' or 'to be fortunate to have' — a passive-like construction where the blessing is received. 知性 (ちせい) means 'intelligence' and 美しさ (うつくしさ) is the noun form of 美しい (beautiful). The と connects the two blessings.