US MAGAZINE reports that Brit’s lil sis, Jamie Lynn, celebrated her 17th birthday last week with Casey Aldridge, her fiancee and baby daddy. Casey and Jamie Lynn marked the occasion by shopping at Wal-Mart and dining at a chain restaurant (no details on which one, alas). the rest of the Spears clan was apparently in LA with elder sister Britney. this slice-of-life vignette makes me want to make a sugar sandwich on white bread. MMMM!