The 47-year-old said it was a case of "my way or the highway" as Black Mirror creator Brooker, 51, originally didn't fancy becoming a husband or a parent.
Speaking on Sophie Ellis-Bextor's podcast Spinning Plates this week, she said: "I always wanted to have kids... but weirdly, Charlie didn't think he ever wanted kids.
"So when we got together, I was like, 'if you're a ‘not a having kids’ kind of person then we're not compatible.' But it turns out he was."
She continued: "I was in my mid-thirties and when you're in your mid-thirties with your body clock ticking, you sort of think,'I don't want to be in another relationship without it going anywhere.
"So yeah, quite quickly it was my way or the highway, which is good because then you know if someone is committed maybe...
"I was literally like, 'there is no point us being together unless you're sure you want to have kids and quite quickly as well.' And If that was to scare him off, then he wasn't the right person."
Despite the filmmaker not initially seeing parenthood in his future, Huq - who he married within nine months of the ultimatum and now shares sons Covey, 10, and Huxley, eight, with - said he's taken very well to fatherhood.
"But he is really good with kids which you might not think cause of his miserable alter ego, but Charlie is a lamb in wolf's clothing," she revealed.
The TV presenter also revealed that what drew her to Brooker is that he could hold a good conversation over the phone, which is "a rare thing" nowadays.
She said: "I don't have an Amazon account, an Uber, a Deliveroo... nothing. I am not even on Facebook, I am an old-fashioned person.
"That was one thing that attracted me to Charlie, a bloke who is good at phone conversations is quite a rare thing, and Charlie is really good at having a telephone conversation.
"I am anti-consumerism. I buy nothing. Me and Charlie yin and yang there well.
"I always say I am really analogue and Charlie is really digital."