Kourtney Kardashian Posts 'Girl Power' Throwback Snap After Khloe Gives Birth

Hours after Khloé Kardashian welcomed her first child — a baby girl — sister Kourtney Kardashian posted an Instagram that seemingly celebrated the newest addition to the KarJenner clan.

Kourtney, 38, took to Instagram to share a photo of her daughter Penelope Disick with who appear to be Kim Kardashian's daughter, North West, and a friend's daughter.

Khloe's baby marks yet another girl to the KarJenner family, with sister Kim and husband Kanye West welcoming daughter Chicago West in January and sister Kylie Jenner and boyfriend Travis Scott welcoming daughter Stormi Webster in February.

The Instagram post marks the first of what appears to be a nod to Khloé's new daughter from the famous family, who has remained mum on both the birth news and the recent Tristan Thompson cheating reports that surfaced within the past two days.

Earlier in the week, Kourtney and Kim were criticized for sharing vacation photos amid the cheating allegations drama, but the two were reportedly by Khloé's side during the birth in Cleveland, where Thompson plays professional basketball for the Cleveland Cavaliers.

Along with the two sisters, mom Kris Jenner and BFF Malika Haqq, Thompson was reportedly present for the birth, despite swelling cheating reports that surfaced during the final days of Khloé's pregnancy.

Sources told TMZ Wednesday that although Khloe was "devastated" about reports detailing Thompson's behavior, she "understands the importance of the birth in the lives of everyone involved."

To that end, the mom-to-be may have taken into account the fact that Thompson is the father of her child and that an important bond can be formed between parents and their children in the delivery room.

The Daily Mail had published photos of Thompson appearing to kiss another woman at a club on April 7, while The Shade Room posted photos of the athlete and what appears to be the same woman entering a hotel. TMZ also got in on the action and released surveillance footage of Thompson appearing to get close to two women at a hookah lounge near Washington, D.C. in October. In the security tape, he can be seen kissing one of the women.

As for what will happen with Kardashian and Thompson, a source told PEOPLE that Kardashian is likely to stay with the NBA player.

"She's a hopeless romantic and she'll try to make this work," the source said of Kardashian. "She tried forever to make it work with Lamar [Odom]. She's having a child with Tristan, and she's going to try to rebuild this."

The source added, "Khloé could probably convince herself to get over the fact that he maybe, kind of, sort of, hooked up with some groupie while out on the road. But being so indiscreet about it and letting it get splashed all over the place and having it humiliate her? That's actually even worse."