Duff, 30, gave birth to her first child, a baby girl, on Monday after being induced over the weekend, Us Weekly reports. She and Rosenberg named their daughter Ryan.
Though Haylie missed celebrating Mother's Day by one day, she tweeted a message of solidarity with her new mom friends on Sunday.
Duff's younger sister, Hilary, hosted a baby shower for Haylie back in March, with guests including Lauren Conrad and Jenna Dewan Tatum, according to Us.
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