The designer and Fashion Star mentor said that Simpson is "definitely" ready to welcome her first child with fiancé Eric Johnson and will be a wonderful mother.
"I think she's going to be amazing. She's the sweetest, kind of down to Earth, All-American girl," Varvatos told US Weekly.
"[Jessica] is a family girl. She's never anywhere without her mum, and her dad's with her all the time. For her, it's really all about family. I think what's so amazing about her becoming a mum is that I think it's kind of finishing off that other missing piece in her family,"
Simpson recently revealed that she and Johnson are expecting a baby girl, and promised that while the name is "non-traditional", it will not be shocking.
She has admitted that she felt very emotional throughout her pregnancy and even cried "big crocodile tears" after feeling the child move for the first time.