。
She's a second Madame Curie.
Literal
She [topic-は] second [genitive-の] Madame-Curie is.
A common figurative pattern: '第二の[famous person]' means 'a second X / a new X / the next X' — used to flatter or predict that someone will rival a famous figure. キュリー夫人 is the standard Japanese rendering of Marie Curie, where 夫人 ('madame, Mrs.') is the standard suffix for foreign married women in formal Japanese (parallel to サッチャー夫人 'Mrs. Thatcher'). The compliment locates the speaker as familiar with Western scientific history.