Feinstein had a way to know due to her position. Why did she not know, or what did she intend to allow China to know?

Emphasis below mine.

BABY, CHINESE SPY CAN DRIVE HER CAR

" ..... Note that Feinstein was chairman of the Senate Intelligence Committee at the time. It is unclear from the column when the Feinstein staffer was recruited.  Another report  indicates that he worked for Feinstein for 20 years. According to the Chronicle column, although Feinstein let the man retire and kept the lid on the story until now, no harm was done. The Chinese, incidentally, take these matters  more seriously. Somehow I doubt that we have heard the full story yet.

President Trump commented on the story on Saturday night at the Ohio rally he held to support GOP congressional candidate Troy Balderson. President Trump  was quoted  in relevant part by the Washington Times: “The leader of the Russia investigation, Dianne Feinstein, had a Chinese spy as her driver for 20 years. And she’s leading the Russian ‘witch hunt.’ Isn’t that something? And then she says to me, ‘What did you know about this and that?’ Give me a break.”

https://www.powerlineblog.com/archives/2018/08/baby-chinese-spy-can-drive-her-car.php