Rob infamously bailed on her wedding to Kanye West but the once tight siblings are supporting one another again in his hour of need.
Kim sent him a positive message on his 30th birthday recently before his relationship with Blac Chyna imploded.
She wrote on her website: "Happy birthday to my one and only robbie!!! You are the best dad, brother and friend. I love you so much and I hope you have the best birthday ever!"
And a source told RadarOnline.com: “Kim and Rob are in touch again and she is supporting him with Blac Chyna and encouraging him to become the best father possible to Dream.
“They used to be really close but Rob’s personal issues got in the way of that but Kim has always supported him and wants him to grow through this process.
“Initially, she had sympathy with Chyna but not anymore and she wants to make sure that Rob knows that she is fully supporting him during this stressful time.
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The relationship between Rob and Chyna imploded this week amid allegations of cheating and when his Instagram account was taken down after he posted some inappropriate images.
And it now looks like the fight could escalate into a fully blown war as the pair battle over their daughter Dream.
The source adds: “Kim no longer trusts Chyna and she will do all that she can to back her brother and make sure that his life does not spiral out of control.”
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