1999 Rolling Stone cover story.But it’s as if she’s describing a dead icon, not the one-time golden girl from this rough slice of northern Louisiana, just a few miles from the Mississippi border, who is still only 39 and very much alive.Gehringer likes to point out the facial resemblance between Britney’s grandmother, Emma Jean Spears, who killed herself at age 31 with a shotgun on the grave of her infant son in May 1966, by gesturing first at a framed photo of a fresh-faced young “Jean,” as