Haylie Duff is going to be a mom again!

The singer, actress and Real Girls Kitchen food blogger is pregnant with her second child with fiancé Matt Rosenberg, she shared on Instagram Friday. Baby-to-be will join big sister Ryan Ava Erhard, 2½, who was born to the couple in March 2015.

“Round 2! Ryan thinks our new baby is growing in HER belly!  #FamilyOf4,” Duff, 32, captioned a cute photo of Ryan pointing at her belly.

A source tells People, “Haylie is so excited to have another baby and for Ryan to be a big sister!”

Duff and Rosenbeg have been together for five years. They got engaged in 2012 when the T-shirt entrepreneur popped the question on April Fool’s Day, but decided to push their wedding back when Duff got pregnant with Ryan.

Motherhood hasn’t been the easiest for Duff. “For me, the biggest challenge has been the pressure to ‘do it right,’ ” she admitted in the Mini Magazine‘s summer 2017 issue. “There isn’t a clear-cut way to be a parent. We will all make mistakes.”

Though she successfully handles a lot—including her children’s clothing line Little Moon Society—Duff confessed, “Sometimes it all comes crashing down but there is such beauty in the chaos.”

There are more high points than low ones still, and some skills she’s learned she had that she didn’t realize she had before. “I never knew I was capable of juggling so many things!” Duff said. “I think that surprised me the most.”

Her priorities also shifted, Duff shared, adding, “It taught me love on a whole different level. It made me realize that this life isn’t just about me and what I want. I have to consider if things fit in to what is going on in Ryan’s world.”

Little Ryan, by the way, is “so funny and adventurous these days.” And until her brother or sister arrives, Ryan still has plenty of time to play with cousin Luca Cruz, her aunt Hilary Duff‘s 5½-year-old son.

RELATED: Hilary and Haylie Duff Are Bikini-Clad Beauties in This Sweet Sister Selfie

“They really play well together,” Duff told People in November. “One time I had Luca for a sleepover and the two of them were outside running around on a Slip ‘n Slide, and I remember looking out at them in the yard being like, ‘This is what they’re going to do as teenagers.’ ”

Added Hilary, “Haylie sent me a picture and Ryan had no shirt on, a diaper and a flower crown. I don’t know what [Luca] had on, but they looked like they had been playing so hard. She was like, ‘Yo, Coachella 2030.’ I’m like, ‘No! Stop!’ If this is a flash into our future, we should be very afraid.”

  • Reporting by AILI NAHAS