Carey Mulligan didn't think her husband Marcus Mumford was "boyfriend material" when they first met.

The 38-year-old 'Promising Young Woman' star first met the musician at camp when she was 12 and he was 10, and Carey has confessed she didn't consider dating the musician but she think he was the "kindest person" she'd ever met.

Speaking on the 'Smartless' podcast, she explained: "We were friends when we were kids. So we went to camp together ... we met when he was 10 and I was 12. We met when we were kids."

When asked if she "hooked up" with the Mumford and Sons star, Carey replied: "We didn’t but I wrote in my diary that he was the nicest, the kindest person I’d ever met and I gave him 9 1/2 out of 10 ...

"I also wrote in my diary that he definitely wasn’t boyfriend material. I mean not that I’d ever had a boyfriend at that time. But I decided that he was not it ...

"We were pen pals for a couple of years then we lost touch and then the internet happened and we were both on Facebook ... and we touched based there and we met again when I was like 24."

She went on to add that shortly after meeting up again for the first time in years, they ended up working together on 2013 movie 'Inside Llewyn Davis'.

Carey added: "What's weird is that we also not long after we met again as adults, we both worked on the Cohen Brothers movie 'Inside Llewyn Davis' and were both independently hired."

The couple married in 2012 and they have three children together. They are parents to Evelyn, eight, and five-year-old Wilfred and recently welcomed a baby daughter, whose name has yet to be revealed.

The new mum recently opened up about the tot, giving her a "10 out of 10 so far".

Speaking to 'Entertainment Tonight' at the Variety Power of Women Los Angeles gala last month, she said: "Oh, she's great. Great. Good baby, 10 out of 10, so far. We'll see how long that lasts."