UK: Scarlett Johansson supports Israel because her mother's Jewish, or something

Via CiF Watch:

Carole Cadwalladr interviewed Scarlett Johansson: in a recent article in The Observer, and there she comes up with one of the weirdest phrasings I've ever seen:

[H]er mother is Jewish and she obviously has strong opinions about Israel and its policies

I doubt Cadwalladr cares about whether Johansson is Halachikally Jewish, and yet, she uses Johansson's mother as a way of explaining.. what?