A sympathetic Solange Knowles says knows the challenge of being a famous teen mother. Or at least a teen mother.

Solange, 21, welcomed son Daniel in 2004 at the age of 18 (she split with husband, former football player Daniel Smith, after the baby was born).

"I'm sure a lot of people perceived that I was gonna be a young, irresponsible mom," Beyonce's sister told Us Weekly recently.

"I think that there are moms who are 35 who are just as irresponsible."

What advice does Solange have for the 17-year-old pregnant Jamie Lynn Spears (whose baby bump is really starting to show)?

"You just have to make the best decisions for you," Knowles said. "You have to decide what's best for you. Who are we to say what's right and wrong for a person?"

To focus on raising her son, Solange Knowles said she "moved to the country for a year" without any nannies or babysitters.

"My parents lived on a whole opposite part of the world," she said. "My son has been my focus ever since the day he was born. He's been the light of my life," she added, "the inspiration behind everything."

Sounds like good advice from another star's younger sister who has been there. At least Jamie Lynn has Casey Aldridge around to help out, as well.