The 53-year-old supermodel has urged the fellow catwalk icon, who is expecting her first child with her fiancé Jason Statham, not to follow in her footsteps and shed the post-pregnancy weight within a short time frame because she believes it is not ''healthy''.
Speaking to the 'Mad Max: Fury Road' actress in an interview for Harper's Magazine about motherhood and fitness, the Australian star - who is also known as The Body - said: ''I was not a good example.
''I was not a good example because I did all that [shedding the weight quickly] for my first child [Flynn] and within three weeks I was back to normal.
''It was not a healthy way of doing it.''
Although Elle has admitted she slimmed down within 21 days after her first child, she ''certainly didn't do it'' again after she gave birth to her 14-year-old son Aurelius Cy.
She added: ''I wouldn't do that again and I certainly didn't do it for my second baby.''
And Elle has urged Rosie and other mothers who are desperate to regain their slender physique after having children to ''take your time'' when working out.
She said: ''If I could give advice to any woman having a baby it's to take your time.''
Elle's health tips come after the 30-year-old model - who has designed her own lingerie, beauty and swimwear line for Marks and Spencer her Rosie for Autograph line - joked she was worried whether she will return to her 26 inch waist and squeeze into her petite size eight clothes after giving birth.
Speaking previously, she said: ''More cake ... questioning if I'll ever fit back into my size 26's again.. (sic).''