Kim Kardashian's daughter is jealous of her baby brother

Kim Kardashian is struggling with her little girl's jealous attacks on her baby brother.

The reality TV star admits three-year-old North has no love for her one-year-old sibling Saint at times and "beats him up all day long".

The tantrums became so dramatic, Kim had to rethink her nursing schedule.

"She's so jealous," the celebrity mom told U.S. talk show host Ellen DeGeneres. "I thought it was a phase (but) it's not going away... I can't hold him (Saint), I have to stop breastfeeding him...

"I had to get a little milk box and put it in the other bra with a straw, so she would drink and he would drink!"

And Kim reveals her daughter is very bright - just like her dad, Kanye West.

"She's really, really smart... She knows how to outsmart us," the Keeping Up With the Kardashians star explains. "She is Kanye's twin - same personality, says the same wild things."