12/20/2007 at 06:00 AM EST
At 12 weeks pregnant
, Jamie Lynn Spears isn't showing – yet. But how should a high-profile 16-year-old dress for the inevitable "bump watch" to come?
"She's a young girl, so I would want to keep [her look] innocent," top maternity designer Liz Lange told PEOPLE at the Great Debaters
premiere in New York Wednesday night. "I think little cute dresses and jeans with tight-fitting tee shirts. ... She's 16, and I'd like to see her look her age."
As for how her style should differ from big sis Britney Spears
, who frequented Lange's L.A. boutique during her two pregnancies, Lange says, "Britney was into cowboy boots with little dresses. That was her style. I'd like to see Jamie Lynn go a little plainer. [No] belly baring for her!"
Lange continued: "I hope she's ready for this – It's definitely a big step. I know that as a mother myself. But if this is what she wants and what their family wants, then mazel tov."