The 28-year-old model has been busy since she gave birth to her second child Dream Kardashian - whom she shares with Rob Kardashian - last month, and sources say she is thankful to the 19-year-old reality star for keeping her four-year-old son King Cairo - whom she shares with Kylie's boyfriend Tyga - ''happy and satisfied''.
A source said: ''Kylie can't do any wrong where Chyna's concerned. Kylie's been a huge help to her by watching King and keeping him happy and satisfied as she deals with her two little babies who require so much of her attention, by the name of Dream and Rob.''
The news of Chyna's friendship with the 'Keeping Up with the Kardashians' star comes as it was recently claimed members of the famous family - which include mother Kris Jenner, and sisters Kim, Khloé, and Kourtney Kardashian - weren't happy with the tumultuous relationship between her and Rob.
The source added to HollywoodLife.com: ''Still, she feels salty that Kris, Kim, Khloe and Kourtney aren't supporting her relationship with Rob Kardashian and she's equally mad at them for excluding her from family functions.''
The engaged pair - who have their own reality show 'Rob & Chyna' - separated last week after constantly fighting with one another, but reconciled just before Christmas to spend the holiday with their new-born daughter.
Recently, it was claimed Chyna had been left off the guest list for Kris' annual Christmas bash as the family ''can't stand'' the constant arguments between the new parents.
An insider said at the time: ''Rob's family is over Chyna. She is not invited to Kris' holiday party.
''Rob's family is trying to distance themselves from Chyna. They can't stand the toxic relationship. They very much care about baby Dream though. It's just come to the point when they think Rob is better off without being in a relationship with Chyna.''