The two, who were in the middle of a nasty social media feud this time last year, posed together for the photos Thursday, even using Snapchat's face-swap feature to take a selfie.
"Hanging out with my lil sis," Chyna -- born Angela White -- captioned one photo found on her account.
In another, found on Jenner's account, the 18-year-old reality television personality teased, "When we've been best friends the whole time."
Chyna is currently engaged to Jenner's half-brother, Rob Kardashian, despite having been once engaged to the Keeping Up WIth the Kardashians star's current boyfriend, rapper Tyga. A 26-year-old model, Chyna is also best friends with Amber Rose, who dated Jenner's brother-in-law, Kanye West, before he married Kim Kardashian.
Tyga and Blac Chyna split in August of 2014, but not before welcoming their son, King Cairo, in 2012. She became engaged to Rob Kardashian earlier this month.