In addition to flaunting her toned legs in a pair of short, rolled jean shorts, the 32-year-old heiress wore a striped, button-down shirt, Ray-bans and black ballet flats while carrying a coffee cup and a handbag that featured big red lips on it.
While Nicky has yet to share a photo of her little girl on social media, she did post a romantic shot last Sunday of her and husband James Rothschild from their wedding day in honor of the couple's one-year wedding anniversary.
"Thankful for the best anniversary gift ever ? our beautiful daughter Lily-Grace," Hilton captioned the throwback wedding shot.
Nicky's big sister, Paris Hilton, also took to social media to gush about her new niece and wish her sibling a happy anniversary.
"Happy 1 Year Anniversary to the most beautiful bride & mother @NickyHilton. I am so happy that you have found such an incredible loving & loyal man to spend the rest of your life with," Paris wrote alongside a black-and-white image from her sister's big day.
"Congratulations on your new baby & starting your family together. Love you 3 so much! ❤️ #RelationshipGoals #FamilyGoals," she added.
It took two days for Nicky to return to social media after becoming a mom, and only three days before she was out and about wearing skinny jeans.
See Hilton's new-mom glow when she first stepped out after giving birth in the video below.