Actress Sienna Miller says her newly pregnant friend Keira Knightley does't need any parenting advice.

"We've spoken a lot and I know she will be amazing," Miller, who has a two-year-old daughter with actor Tom Sturridge, told Page Six at the premiere of "American Sniper".

It seems that Knightley, who is expecting her baby with rocker James Righton, is well prepared for motherhood.

"She doesn't need any advice. She will be perfect," Miller said.