On Thursday night, the Stranger Things star told her Instagram followers that she and Jake had adopted a baby earlier in the summer.

"This summer, we welcomed our sweet baby girl through adoption," the couple announced in a joint statement. "We are beyond excited to embark on this beautiful next chapter of parenthood in both peace and privacy."

"And then there were three..." she added.

Millie and Jake have been in a relationship since 2021, and tied the knot in May of last year.

The 21-year-old has previously made no secret of her hopes to start a family in the near future, telling the Smartless podcast earlier this year: "For me, my home is full of love for anyone and anything.

"So that's kind of where we're at. We're wanting to start a family and it doesn't matter in what way or when, but it will happen for sure."

Pointing out that both herself and her husband have three siblings each, she continued: "I really want a big family. I'm one of four, he's one of four, so it is in our future."

Elsewhere in the interview, Millie shared that she has been focussed on becoming a mother since a young age, pointing out that her own mum was 21 when she was born.

"Since I was a baby, I told my mom, like 'Baby dolls [are what I want]'," she explained. "I wanted to be a mum just like the way my mum was to me.

"Jake knows how important it is to me. Like, of course I want to focus on really establishing myself as an actor and as a producer but I also find it's so important to start a family for me personally."

Millie shot to fame around a decade ago as a child actor in the Netflix series Stranger Things, which is coming to an end later this year.

Since then, she's made a name for herself as both an actor and producer, most notably in Netflix's Enola Holmes movies and the films Damsel and The Electric State, both made in connection with the streaming giant.