This is the 222nd most frequent Polish word.
ona
"She" or "her" in English, referring to a female subject or object.
The word 'ona' is used as the subject of the sentence, representing a female person.
Ona jest bardzo miła.
She is very kind.
Here 'ona' refers again to the subject, mentioned previously as the one making a decision.
To była jej decyzja, ale ona się nie zawahała.
It was her decision, but she did not hesitate.
The word 'ona' is used to emphasize who is being talked about in this question, referring to a female.