What do you buy for your pregnant and engaged sister, who’s about to turn the ripe old age of 17?

That’s the question that must have been going through Britney Spears‘ mind, as she shopped for Jamie Lynn’s birthday, which happens to be today. Happy sweet seventeen, mama-to-be!

Britney and her mom, Lynne, headed out yesterday the corporate offices of clothing store Ed Hardy, to peruse some items for JL. According to a rep for the store, Brit was “in good spirits” as she shopped. Later, the pop star visited designer Christian Audigier and to check out his new spring collection. “Christian and she were laughing as she tried on Ed Hardy sunglasses and checked out the bathing suits,” says the rep.

So what will Jamie Lynn score form her big sis? Britney picked up a bunch of Christian Audigier handbags, scarves, and Crystal Rock T-shirt for Jamie Lynn, and also bought some items for her dad and brother…

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