Blake Lively's older daughters found having a new baby sister a ''tough adjustment''.

The 'Rhythm Section' actress and her husband Ryan Reynolds welcomed their third child into the world three month ago and while five-year-old James is ''very into'' the baby, three-year-old Inez has been less than impressed.

Speaking on 'The Tonight Show Starring Jimmy Fallon', she said: ''It's a bit of a tough adjustment in our house. My oldest is very into the baby, but my middle child, not so much.''

Blake tried to get Inez excited about being a big sister by highlighting how important she would be in the baby's life.

She recalled telling her: ''You're going to teach her everything she knows.

''You get to teach her about cities, and the sky, and flowers, and Santa Claus, and Mickey Mouse, anything she wants.'

Blake added: ''She goes, 'Ohhhhh. I didn't love you. But now I do.' Speaking like Jennifer Aniston in 'Friends!'' Just a cute little thing.''

The 32-year-old star admitted her eldest daughter feels ''very, very intimidated'' by Jimmy because the talk show host is ''like Beyonce'' to the youngster.

Laughing, she told the presenter: ''I was coming here tonight, and she was like, 'It's fine, it's fine. Just go.' And I was like, 'Come on'. And she's like, 'No, it's okay. It's fine. It's fine.'

''She's like, buddies with Taylor Swift. Jimmy Fallon? Can't speak.

''You are Beyoncé to her. We have, like, Jimmy Fallon cardboard cutouts in our house. Yeah, she's very, very, very intimidated.''

Elsewhere on the show, Blake revealed her hand injury - which required two surgeries and a break from filming 'The Rhythm Section' - occurred while shooting a fight scene with Jude Law.

She explained: ''I punched his elbow, which you don't really want to punch someone's elbow, you want to aim for the face.

''My hand just like, basically turned to party confetti. It was just like, whoosh, upon contact.

''I separated this ligament here, so my knuckles are kind of dropped. Then I dislocated these two bones, and broke some things.''