LOSANGELES: JESSICA SIMPSON is desperate to become a mother, according to her sister ASHLEE SIMPSON-WENTZ.

The singer/actress, who recently broke up with her American footballer boyfriend Tony Romo, dotes on nephew Bronx, her sibling's son with rocker Pete Wentz.

She was forced to deny reports she was pregnant earlier this year (09) - but Simpson-Wentz reveals her older sister is getting broody.

Ashlee says, "She's always saying, 'Oh, I want a baby.'"