In an interview with InStyle magazine, the 34-year-old actress said being a stepmother to Polish's daughter, Jasper, 16, made her want to have her own children, reported E! News.
"After ordering pizza for the third time when she first started coming over, I knew I had to learn how to cook because I wanted to nurture her. These maternal instincts kicked in," Bosworth said.
The "Young Americans" actress added she and Polish had given parenting a thought and felt they will handle the situation in good humour.
The couple married last year, after Polish proposed to her back in 2012.