Elle Macpherson says becoming a stepmother has been the ''biggest gift''.

The supermodel-turned-lingerie designer inherited three more children as a result of her marriage to billionaire Jeffrey Soffer in August 2013, and she treats them exactly the same as her own sons, Flynn, 16, and Cy, 11, whom she shares with ex-husband ARPAD BUSSON.

She said: ''Becoming a stepmother has been the biggest gift and I cherish my relationship with all five children. I think love does wonders for every woman. Being a mother is my greatest achievement and my sons are a credit to themselves.''

The statuesque beauty - who earned the nickname 'The Body' for her stunning figure as a model - has no qualms about recently turning 50 and admits the milestone birthday passed without much contemplation as she is so happy living her life.

She explained to Australia's WHO magazine: ''I never really gave much thought to turning 50. I feel loved, balanced, happy and healthy. I'm feeling good on the inside, which is more important to me now than how I look.''

However, Elle was moved to tears by a homemade video of birthday messages created by her close friends and family.

She added: ''It took me four times to watch it through my tears. It was the most beautiful gift.''