Grimes, Elon Musk's ex, is speaking out in support of his estranged trans daughter

• Elon Musk has an estranged relationship with his transgender daughter, Vivian Jenna Wilson.
• Wilson has fired back at Musk after he said that she's "not a girl."
• But Grimes, who shares three children with Musk, said she's "endlessly proud of Vivian."

Elon Musk's former partner, Grimes, has spoken out in support of the Tesla chief's daughter, Vivian Jenna Wilson.

"I love and am forever endlessly proud of Vivian," Grimes wrote in an X post on Thursday.

The singer's comments came hours after a bombshell NBC News interview with Wilson was published Thursday evening.

Wilson accused Musk of being a "cruel" and absent father in the NBC report.

"He was cold," Wilson said of Musk. "He's very quick to anger. He is uncaring and narcissistic."

In her interview with NBC, the 20-year-old Wilson also slammed Musk for making anti-trans comments this week. Musk on Monday wrote on X several claims about Wilson, including an assertion that Wilson is "not a girl."

"I think he was under the assumption that I wasn't going to say anything and I would just let this go unchallenged," Wilson told NBC. "Which I'm not going to do, because if you're going to lie about me, like, blatantly to an audience of millions, I'm not just gonna let that slide."

It's notable that in her support of Wilson, Grimes referred to her as "Vivian." Musk in his social media post referred to his daughter by her deadname.

Wilson is one of the 12 children that Musk shares with three different women — his ex-wife, Justine Musk, Grimes, and Neuralink executive Shivon Zilis.

In August, Grimes told Wired in an interview that she did have a "big, long conversation" with Musk about his views on transgender people because she wanted to understand where he was coming from.

"It came down to pretty much every way that your transition can cause fertility issues. I was like, 'OK, you don't hate trans people, you hate woke culture,'" she said of her conversation with Musk.

The pair are currently embroiled in a custody battle over the three kids they share — X Æ A-Xii, also known as X; Exa, also known as Y; and Techno Mechanicus, or Tau. Both Musk and Grimes have filed dueling lawsuits in Texas and California, respectively.

Representatives for Musk and Grimes did not immediately respond to requests for comment from Business Insider sent outside regular business hours.