(Cover) - EN Showbiz - Jennifer Lopez has been trying to convince her children how "wonderful" sleep is.

The 41-year-old actress-and-singer and her musician husband Marc Anthony, 42, are proud parents to three-year-old twins Emme and Max.

Jennifer admits balancing her hugely successful career with motherhood can be challenging, notably because the youngsters don't yet appreciate the value of a good night's rest.

"They won't let me sleep at night and then they'll wake up very early. I ask them, 'Why don't you sleep anymore? Sleep is so wonderful! Believe me, you're gonna love to sleep when you're teenager!'" laughed the star to Germany's in magazine.

"But it's useless: They won't listen to me!"

Jennifer, whose seventh studio album Love? has taken the charts by storm since its release in April, added that being apart from Emme and Max is "the worst feeling". The songstress has had a busy 2011 so far, promoting Love? as well as appearing as a judge on season ten of talent show American Idol, which aired from January to May. Jennifer admits her hectic schedule did get to her at times.

"I used to have like boundless energy. And now? Forget it! I used to able to work the whole day, never needed one day off - and now I sometime yell: 'Please, I need a break!'" she laughed. (C) Cover Media