Duff and Koma share daughters Banks, 3, and Mae, 8 months. Duff is also mom to son Luca, 9, from a previous marriage.
The couple has opened up about expanding their family in the past. In August, Koma praised his wife in a sweet post that also hilariously included her Subway order, causing Duff to comment, "Oh you’re gunna get it. This is bound to get him baby number 4 and subway night 3 tonight."
Shortly after Mae's birth, Duff spoke on Dr. Berlin's Informed Pregnancy Podcast about whether she wanted more kids, saying she wavers, and adding of Koma, "I think he totally would be down, but he recognizes that I have to do all the work."