Kim & Khloe Kardashian, Kris Jenner to Attend Tristan Thompson's Mom's Funeral

Kim Kardashian, Khloe and Kris Jenner want one thing to be very clear to Tristan Thompson -- they're gonna support him in one of the hardest times of his life, as they all plan to be with him when his mom is laid to rest.

Sources with direct knowledge tell TMZ ... the trio is planning to fly to Toronto later this week to be in attendance for Andrea's funeral. We're told Tristan paid for and planned the whole service, which will be an intimate and beautiful celebration of her life.

Much like Khloe did last week, when Andrea died unexpectedly, we're told Kim, Kris and Khloe want to be there to comfort and support Tristan. Sources tell us it's important to the Kardashian clan to be there for loved ones, especially during tough times like this.

TMZ broke the story, Andrea suffered a heart attack at home last week -- she was rushed to a local hospital where doctors tried to resuscitate her, but she didn't make it.