Keira Knightley was "not ready" for her youngest daughter to start walking whilst the family was in lockdown.
The 35-year-old actress has claimed her daughter Delilah, 12 months, managed to start walking around their home at just nine months old, which left Keira and her husband James Righton scrambling to keep an eye on their brood as they also had energetic toddler Edie, five, to look after.
She recalled: "We went into lockdown when [Delilah] was about six months, so she's had a very strange life. And that sort of involved my then-four-year-old, who turned five in lockdown, running around [her baby sister] a lot, because we couldn't go out.
"The baby, who I thought would be [sitting] and very easy to look after for quite a while, at nine months, just decided to get up and start walking."
The 'Atonement' star then joked that she "didn't even think" her child walking at nine months old "was possible", as "it didn't look physically possibly" because of the size of her feet.
She added: "Big butts and tiny little feet. I think, at any other point, if we hadn't been locked down, I would've been like, 'Whoa, my kid's a genius!' And as it was, I was just like, 'Sit the f*** down. We are not ready for this, as well.' "
Keira also insisted Delilah "didn't crawl at all" and instead just skipped straight to walking.
During an appearance on 'The Tonight Show starring Jimmy Fallon', she quipped: "We put her on her belly to crawl and she'd look at you like, 'What the f*** are you doing? I'm not doing this.' "
The 'Begin Again' actress previously spoke about the stresses of motherhood when she joked she hadn't brushed her hair in six weeks following the birth of her youngest daughter.
Speaking in November last year, she said: "You can tell I've got a six-week-old baby. I'm talking, but I've got no idea where I'm going. This is about the first time since I gave birth that my hair has been brushed - and I didn't brush it. Lovely Luke, who is my hairdresser today, he brushed it. I was in my pyjamas when they got there and this is somebody else's dress."