Jennifer Lopez's children could be her backing singers.

The 43-year-old star says Max and Emme - her four-year-old twins with ex-husband Marc Anthony - love watching her perform and know all the lyrics to her songs.

Related: Jennifer Lopez at German game show

She said: "They watch the show almost every night - they love it, they're excited by it.

"We were having lunch and I started singing 'Cause I have spent all of my life' [from 'Waiting for Tonight'], and at the same time both of them go, 'Waiting for tonight, oh-oh'. It was hilarious.

"I could employ them as back-up singers. They'd be cheaper."

Jennifer - who is dating dancer Casper Smart - admits she is at her happiest spending time at home with the children.

She told Australia's Daily Telegraph newspaper: "The best thing about being a mom is the love you feel and the joy they bring to you.

"I'm never happier or more complete than when I'm lying in bed with my babies, watching a movie."

And the former 'American Idol' judge says being a mother has put her career into perspective and she is much more relaxed.

She said: "I'm better at saying no now. As long as they're all right and healthy, and I'm healthy for them, that's all that matters.

"It helps you go, 'Everything can wait.' Whereas before, it was more like, 'Ah, I have to do that, I have to stay up.' Now it's like, 'You know what, it'll be there in the morning. I'm going to sleep now and I'll see you in the morning.' "