In the photo seen below, Duff also confirmed that she and Rosenberg are expecting, and even shared the baby's gender with fans! The two are set to be the proud parents of one stylish little girl.
"Happiest girl in the world! Finally can let everyone know that Marry @mrs_sts and I are expecting! #BabysFirstJordans," she captioned the photo of the super adorable pink, white, and black baby sneakers. She also shared a photo of her growing baby bump.
The couple got engaged when Rosenberg popped the question in April and, since then, the pair has been dutifully planning their big day. In June Duff confirmed to People that she and Rosenberg would wed in California, and that the whole affair would be relaxed without being overly casual. "We want it to be something that everyone has a good time at, and if your feet hurt in your heels... take them off!"
So what does their happy news mean for the wedding? Our guess is adding a daughter to their family won't change plans one bit since Duff has already shared they wanted to enjoy a long engagement. "Are we slacking?" Duff asked on Access Hollywood Live earlier this month when questions about her wedding date. "We're just really enjoying this phase of our relationship. I feel like so many people get engaged and then it's like 'Ok, we have to get married within a year' or whatever it is. We're just enjoying being engaged. It's fun to be a fiancé."
Whenever they do tie the knot, Duff has made it clear the event will be very family-oriented. "My dad would walk me down the aisle and Hilary would be maid of honor," she shared.
With a daughter on the way, it seems like nephew Luca will have a partner to walk down the aisle with!