。
She said she wanted to know about it.
Literal
She [topic-は] that [about-について] want-to-know [quotative-と] said.
An embedded clause inside ~と言った: 知りたい ('want to know') is the desiderative form of 知る. Note that ~たい is fine for the speaker themselves but suggests something different in third-person reported speech — here it's embedded inside a と clause as the original speaker's words, so 知りたい is the woman's own first-person assertion as she said it. Without the quote frame, you'd need 知りたがっている ('appears to want to know') for a third-person desire. The と is the quotative particle, marking the embedded speech.