She was an ugly duckling in her childhood but grew up to be a beautiful woman.
Она была гадким утёнком в детстве, но выросла красивой женщиной.
Definitions
The term 'ugly duckling' refers to a person or thing that is perceived as unattractive or unremarkable in their early stages but later develops into something beautiful or admirable, often used to describe personal growth or transformation.