(Cover) - EN Showbiz - Heidi Klum thinks having several children is a "huge responsibility" and she finds it a challenge to "juggle" all of her obligations.

The 38-year-old supermodel has four children, daughter from a previous relationship Leni, seven, and Henry, five, Johan, four, and nine-month-old Lou with her husband Seal. The main difficulty for Heidi is providing all the disparate maternal nourishment that four personalities need.

"It's a huge responsibility to have four kids," Heidi told Us Weekly. "They all have different likes and dislikes and activities that they want to do. You have to learn how to juggle all of that, and at the same time, give them each the love that they need."

Heidi is most concerned with supplying the time and attention to keep everyone happy. With so many people to care for, sometimes it is difficult to focus on everyone's needs.

"When you have one [child], you can focus on one. With four, you have to make sure [your attention] is all spread out just right," said Heidi. "You have to understand how different they all are! And at the end of the day, there is not much time left for you!"

Heidi does manage to find enough time to be a stable matriarch. Her children are much more close as a result of her efforts.

"They always stick together and take care of each other," said Heidi. "They love each other! They love helping Lou. They like to feed her [and] they include her in all their activities."

The newest season of American Project Runway began in America in July. (C) Cover Media