Kate Gosselin celebrated the 20th birthday of her sextuplets with a rare photo of them all grown up.

However, two of the six kids made famous through the reality TV show "Jon & Kate Plus 8" were missing from the celebration as the family continues to deal with the dramatic fallout years later.

"No more teenagers in this house! Happy 20th birthday, my forever babies!" Kate captioned the photo of Alexis, Aaden, Leah and Joel. Collin and Hannah live with their father, Jon Gosselin.

"I love you! Who feels old? I know I do! #20yearsold #ItsaPICKLE."

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INSIDE KATE GOSSELIN'S LIFE IN NORTH CAROLINA NEARLY TWO DECADES AFTER RISE TO FAME

4 of Kate Gosselins sextuplets

Kate Gosselin shared a rare photo of four of her sextuplets on their 20th birthday. (Instagram: Kate Gosselin/Getty Images)

Kate Gosselin in a black dress with a choppy short haircut smiles next to Jon Gosselin in a tan blazer and dark sweater

Jon and Kate Gosselin share eight children together. They divorced in 2009. (Amy Sussman/WireImage for Discovery Communications)

Collin and Hannah chose to live with their father after the fallout from "Jon & Kate Plus 8."

Kate and her husband Jon shot to fame after giving birth to twins and sextuplets. The couple signed on to do two documentaries about their large family in order to make ends meet, but their popularity instead turned the family into reality TV royalty. 

However, the couple eventually separated, then divorced, and it was all caught on tape.

Jon & Kate Plus 8

The couple starred on TLC's "Jon & Kate Plus 8." ( TLC)

According to an episode of Vice's "Dark Side of the 2000s," following his parents' split, Collin allegedly began to act out and rebel during filming, sometimes giving "completely silent interviews" and refusing to interact. 

Collin was allegedly diagnosed with a behavioral disorder and sent away to a separate school at the age of 12. Kate sent Collin to live at the Fairmount Behavioral Health System — a psychiatric hospital located in Philadelphia — without telling anyone in the family. 

"I was not able, with my own resources here, to meet his needs," Kate said during an episode of "Kate Plus 8."

Hannah Gosselin and her brother Collin pose for a photo

Jon Gosselin has maintained a strong relationship with both Collin and Hannah. (Jon Gosselin Instagram)

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However, Collin later claimed during an episode of "Dark Side of the 2000s" that Kate sent him away because he was telling people about the way his mother was treating him at home, which he labeled "abusive." He claimed that she had to put him "somewhere where [he] wouldn't be able to put the secrets out."

In a 2016 interview with "Good Morning America," Kate denied the abuse allegations, saying they were "absolutely" unfounded.

Eventually, Collin wrote his dad a letter in 2017 asking for help, with the address of the Fairmount included. Once Hannah, one of the sextuplets, found out her brother had been sent away for over a year, she requested to move in with her father. Jon was awarded full custody of Hannah as he battled to have Collin removed from a separate psychiatric facility in Pittsburgh. 

"I spent $1 million to get my son out," Jon admitted. The reality TV star used testimony and psych evaluations to help build his case. "Everything I had, I spent."

Jon Gosselin leaves court

Jon Gosselin fought for custody of Hannah and Collin. (William Thomas Cain/Getty Images)

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Hannah is the only sibling that has a relationship with Collin. 

"They don't talk to Collin," she explained during the Vice episode. "Everyone eventually found out what happened to him, but now they've just decided to not have a relationship with him." 

Collin hasn't spoken to the other six of his siblings since 2016.

"I think my mom kind of drove a social barrier between us. She told the story one way, and obviously I see the story a different way."

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