"Khloé has always been very close with Dream," the source says

Khloé Kardashian is supporting her brother Rob Kardashian‘s reported attempt to seek primary custody of his 3-year-old daughter Dream with ex Blac Chyna, a source close to the famous family tells PEOPLE.

“Khloé has always been very close with Dream,” the source says. “When Rob had custody of her as a baby, Khloe often helped out. She really loves Dream.”

“Khloé will do everything she can to help Rob get custody,” the source adds. “She thinks this is best for Dream.”

The Keeping Up with the Kardashians star has a close relationship with her many nieces, Dream included. In September, Khloé documented a playdate between Dream and her 20-month-old daughter True Thompson, whom she shares with ex Tristan Thompson. She can also be seen babysitting Dream on episodes of the family’s E! reality show. Khloé and Rob are particularly close; he even lived with her for a time.

Khloe Kardashian Rob Kardashian Blac Chyna
From L to R: Khloé Kardashian, Rob Kardashian and Blac Chyna
| Credit: Stefanie Keenan/Getty; Gabe Ginsberg/Getty; John Photography/Shutterstock
Khloe Kardashian and Dream cutest moments
Dream Kardashian and Khloe Kardashian

On Tuesday, TMZ reported that it had obtained a sealed court filing in which Rob, 32 alleged that Chyna, 31, is constantly hosting parties at her home while Dream is present. TMZ also reported he alleged that Chyna “snorts cocaine,” is always drunk and spends “$600 on alcohol” daily. Khloé reportedly made a statement in the filing, claiming that Dream has been “decidedly more aggressive” lately and says she doesn’t want to go home to Chyna, TMZ reported.

PEOPLE has not independently reviewed the alleged court filings, and a representative for Chyna has not responded to PEOPLE’s request for comment.

According to the outlet, in the sealed court papers, Rob accuses Chyna of being violent, citing one occasion where she allegedly threw “sharp objects” at her hairdresser.

Rob also claims that Chyna’s alleged partying ways have affected Dream’s behavior, as the child now allegedly uses foul language and is violent with other children, the website reports.

Rob is seeking to have Chyna’s parenting time reduced to just weekends with a nanny present, according to the filing obtained by TMZ.

Credit: Gabriel Olsen/WireImage; Phillip Faraone/WireImage

The former couple agreed to joint custody in September 2017 following a whirlwind romance and failed engagement that culminated with both alleging abuse in separate lawsuits.

In July 2017, Chyna accused the reality star of violating California’s revenge porn laws by posting graphic and expletive-ridden content about her — including three naked photos — while accusing her of drug/alcohol abuse and infidelity. Chyna also claimed in court documents obtained by PEOPLE that he allegedly hit her and threatened to kill himself multiple times.

RELATED VIDEO: Blac Chyna Says She and Rob Kardashian Have ‘No Animosity’ Over Co-Parenting 2½-Year-Old Dream

At the time, Rob denied the allegations of verbal and physical abuse made by Chyna and claimed in court papers that Chyna “did not suffer any injury or harm as a result of any conduct.” A judge later issued a set of restraining orders against him. The parties’ lawsuit has not yet been resolved.