London, Sep 11 - American singer-actress Jessica Simpson really wants to become a mother, according to her sister Ashlee Simpson-Wentz.

Simpson, who recently rekindled romance with ex-beau John Mayer, dotes on nephew Bronx, her sibling's son with rocker Pete Wentz, reports contactmusic.com.

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

'She's always saying, 'Oh, I want a baby',' said Simpson-Wentz.