Forget sibling rivalry, Solange Knowles would rather sing her older sister Beyonce's praises.

Though Solange was the first among the sisters to become a mother, she said Beyonce makes it looks easy with two-year-old daughter Blue Ivy.

"I have never seen anything like it in my life, from anyone. It's absolutely insane," Knowles told the latest issue of online fashion magazine ASOS.

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ASOS

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"Now that she's become a mother, and the way that she's able to balance that is so inspiring," said Knowles, who appears on the cover. "If I am ever feeling like I want to open up my mouth and complain about how hard I am working, I think, 'Uhhh! Sit down!'"

The 27-year-old "Losing You" singer is a single mother to nine-year-old son Daniel Julez.

A regular on the red carpet, Knowles also told ASOS that her personal style is changing.

"I might be having a little evolution in my style…it's been a lot more subtle," she said. "I had a bit of print fatigue, it's been a part of who I am for as long as I can remember. But you want to evolve and experiment - that's part of the fun and the joy of being a woman."