I remember reading an interview from his first wife, I can't find it online anymore, here is an article that talks about: https://www.tyla.com/entertainment/celebrity/elon-musk-first-wife-justine-wilson-remark-why-divorce-790646-20250402

In short, she had 6 kids from Musk, 2 times triplets, all artificial inseminations, one of them is his only daughter Vivian.