Gigi and Bella Hadid 'Have Grown Closer' Since Zayn Malik Was Charged with Harassment: Source

“Bella has stuck by her side, as the situation has caused a lot of tension within the family,” a source tells PEOPLE

Photo: Patrick McMullan/getty

Bella and Gigi Hadid's sisterly bond has become even stronger following the altercation that took place between their mom, Yolanda, and Gigi's ex, Zayn Malik, a source close to the Hadid family tells PEOPLE.

"Gigi and Bella have grown closer since the Zayn and Yolanda incident. Bella has stuck by her side, as the situation has caused a lot of tension within the family," says the source.

Malik, 28, was charged with four counts of harassment after an incident in September in which he allegedly "grabbed [Yolanda] and shoved her into a dresser, causing mental anguish and physical pain," court documents obtained by PEOPLE said.

Gigi Hadid, Yolanda Hadid, Bella Hadid. Bryan Bedder/Getty

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"Gigi is done with Zayn. She's a really private person, so Bella has really been there to support her," the source continues. "It's been tough on all of them because they're all so close. That's her mom, but it's still her baby's father, even though their romantic relationship is over."

Adds the insider: "This has not been easy on Gigi and has caused a lot of stress on relationships with her family."

Reps for the Hadid family did not immediately respond to PEOPLE's request for comment.

RELATED VIDEO: Gigi Hadid 'Has Made It Clear Her Daughter Needs Her Dad' Zayn Malik After Yolanda Argument: Source

In October, Malik responded to a report published to TMZ in which he allegedly struck Yolanda during an argument, writing in part on Twitter, "This was and still should be a private matter but it seems for now there is divisiveness and despite my efforts to restore us to a peaceful family environment that will allow for me to co-parent my daughter in a manner in which she deserves, this has been 'leaked' to the press."

In a statement to the outlet, Malik "adamantly" denied striking her, saying: "I hope that Yolanda will reconsider her false allegations and move towards healing these family issues in private."

Having pleaded no contest to the charges, Malik is required to serve 90 days of probation for each of the four counts; he must also complete an anger management class and a domestic violence program and is barred from having contact with Yolanda or McMahon.

Gigi Hadid, Zayn Malik. Darren Gerrish/WireImage

Malik and Gigi, 26, share daughter Khai, 15 months, together.

Shortly following the alleged altercation between Malik and Yolanda, 57, Gigi and the former One Direction star ended their romantic relationship, multiple sources confirmed to PEOPLE in October. "They are not together right now. They are both good parents though," said a Hadid family friend. "They co-parent. Yolanda is of course very protective of Gigi. She wants the best for her daughter and grandchild."

In October, Gigi penned a sweet tribute to her younger sister on her 25th birthday on Instagram, sharing an adorable photo of Bella doting on Khai. "She's my baby sister but also a firecracker of a spiritual body guard and a forever protector as an auntie," Gigi wrote in part. "I love you more every sun-lap."