United Kingdom, March 11 -- Scarlett Johansson wants to "preserve" her children's privacy for as long as she can.

The 40-year-old actress has Rose, 10, with ex-husband Romain Dauriac as well as three-year-old Cosmo with Colin Jost and explained that she wants them to realise that "anonymity" is something that cannot really be reversed once it is given up.

She told InStyle: "If anyone knows me, I definitely over-share. I'm not a closed book, you know? No. I'm politically active and vocal about it. But I am a private person in the sense that I value my close friendships. My family is very precious to me, as is their privacy. The anonymity of my children is very precious to me. I was talking to my daughter the other day, because she said, ...