"Kate and Jamie are desperate to start a family," said a source.
Moss, 43, who is married to rocker Jamie Hince, is making efforts to gain weight to welcome a new member in the family, reported Daily Star online.
"Kate wants nothing more than to give her daughter Lila Grace a little brother or sister but it is just not happening. She has decided that if she puts on some weight she might have more chance of falling pregnant."
"Since Kate has moved to Highgate she has fallen in love with the hog roasts at her local the Red Lion And Sun," the source added.
