。
She grew up to become a great scientist.
Literal
She [topic-は] grew-up [and-て] great scientist became.
偉大な (いだいな) means 'great' or 'eminent' — a strong adjective reserved for significant accomplishment, not casual praise. You wouldn't call a friend 偉大 for passing an exam. 科学者 (かがくしゃ) means 'scientist' — using the productive 者 suffix that turns a field into its practitioner: 科学者, 音楽家, 芸術家. The 成長して...なった pattern captures the narrative arc of a life: childhood leading to eventual greatness.