United Kingdom, March 24 -- Sienna Miller is finding being pregnant in her 40s "so much easier" than her 20s.

The 44-year-old actress is expecting her third child, and she says being pregnant in her 40s is "the best" because her life is in a "more grounded space" now.

Sienna - who has a two-year-old daughter with actor Oli Green, and 13-year-old daughter Marlowe with her ex-boyfriend Tom Sturridge - told Glamour magazine: "Having had a baby at 29, and then having a baby at 42, and now 44, it's so much easier when you don't have the conflict of feeling scattered and like you want to be doing X, Y, Z.

"If I'm in bed at 9 p.m. with a book, I'm so happy now.

"And now I've got the excuse to do it.

"Life is in a more grounded space. I thin...