The 22-year-old star - who shot to fame alongside twin sister Ashley in hit US TV show 'Full House' aged nine months - has sparked rumours she is expecting her first child after her weight shot up to 102lbs, according to National Enquirer magazine.

A source said: "Mary-Kate has been looking a lot rounder recently. It is good she has put on weight, because she previously suffered from anorexia, but a lot of people think she could actually be attempting to hide her pregnancy."

Mary-Kate has been dating New York artist Nate Lowman since the beginning of the year and is said to have been inspired to start a family by late actor, and close friend, Heath Ledger - who told her becoming a father was the most rewarding thing he had ever done.

The source added: "Mary-Kate really took Heath's words to heart. She wanted the same kind of fulfilment in her life that Heath found in his after becoming a dad.

"She is really happy with Nate and is very excited they will soon be starting their family together."

WENN