Teen Idol Hilary Duff Is Already Expecting Her 4th Baby - 'Wow! At Your Age!' Fan Reacts

Former child star Hilary Duff shocked her fans with an announcement on her family Christmas card. Fans talked about Duff's age in response to her Instagram announcement this week.

Hilary Duff has been beloved in Hollywood since she was a tween, starring in "Lizzie McGuire" and many other famous titles. As her career has slowed down in recent years, she has focused on raising a family.

36-year-old Duff and her partner, Matthew Koma, have a blended family of three children, and Duff recently announced that they were expecting their fourth. She posted a family Christmas card on Instagram and captioned it: "Surprise surprise."

Fans were shocked by the announcement, with one saying: "Wow! At your age!" and another remarking "NO WAY." Another noted that Duff was giving everything in their mid-30s hope that they would still be able to welcome children.

Koma also shared the announcement on Instagram, sharing the same photo and captioning it, "baby #4 is loading." His post was met with congratulations and happiness for the couple.

Duff welcomed her first child, a son named Luca, with her ex, Mike Comrie, in 2012. She then welcomed two daughters named Mae and Banks with Koma. She once shared that it is sometimes difficult, although she tries to be hands-on.

She joked that she and Koma sometimes felt like they weren't old enough to handle some of the things having kids threw at them, but said, "But I think it just empowers you. I think I feel really empowered as a mom of three, and I feel super capable, and I feel super lucky."

Duff also said that she loved having a career and something to do outside of being a mother but that having children was a large part of her identity. The "Lizzie McGuire" alum shared that motherhood was sometimes challenging but extremely rewarding.

Although having three children has led to "mayhem" in her home, Duff says she loves it. She admitted that she loved the pressure of wondering how she would get through a day and the fact that her children thought hugs made everything better.