The 29-year-old soon-to-be mother confirmed the pregnancy herself on Instagram and hinted she's having a girl, sharing a picture of tiny pink Jordan sneakers, reported Us magazine.
"Happiest girl in the world! Finally can let everyone know that Matty @mr_sts and I are expecting! BabysFirstJordans," she captioned the adorable kicks.
Haylie and Rosenberg announced their engagement this past April on Instagram with a picture of themselves and her massive rock.