The Simpson-Johnson family
05/20/2013 at 02:20 PM EDT
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."