updated 05/20/2013 AT 2:20 PM ET
•originally published 05/20/2013 AT 4:30 PM ET
Jessica Simpson is almost ready for baby no. 2!
With her due date quickly approaching, the Fashion Star mentor, 32, kept it casual for a Sunday lunch date at King’s Fish House with fiancé Eric Johnson and their daughter Maxwell, who turned 1 earlier this month.
Wearing fitted workout gear, Simpson’s burgeoning bump led the way while Johnson, 33, toted their tot.
Maxwell may be young, but she has an idea that a baby brother is on his way, the singer says.
“She knows something’s up,” Simpson told PEOPLE at her April baby shower. “Maxwell is so cute because she’ll touch my tummy and she ll laugh and she’ll give my belly kisses.”