Kelly Clarkson will turn 30 next year. By then, Idol's favorite ex-waitress will have grown from America's sweetheart (see: 2004's Breakaway) to a slightly goth brooder (2007's My December) to pop's resident angry grrrl (2009's All I Ever Wanted) right before the proud eyes of Mom and Dad or as we call them, Paula and Simon. In 2011, she's still young enough to pull off gleefully bratty kiss-offs like ''Einstein,'' on which she does the math for a no-good boyfriend: ''Dumb plus dumb equals you.'' But it may not be long before she can't get away with writing songs with ''suck'' in the title.
So it's the perfect time for Stronger, Clarkson's older-better-tougher-smarter album. The excellent pink-bubblegum explosion ''I Forgive You'' plays like a heartfelt postscript to the guy who left her in ''Since U Been Gone,'' with Clarkson's lived-through-this vocals making the lyrics even more poignant: ''We were just a couple of kids...no shame, no blame.'' She's got Gwen Stefani's just-a-girl strut down on ''You Can't Win,'' a punchy guitar rave-up about making peace with your inner walking disaster. Best of all is ''What Doesn't Kill You (Stronger),'' a throbbing glitter-disco tribute to believing that it really does get better. (By the time you finish this review, 9,000 pride-parade DJs will have already added it to their playlists.) Clarkson's voice is made for anthems, and too many of the slow, snoozy ballads here don't do it justice. But she pulls off the downtempo ''Mr. Know It All'' because you're never too old for a good wag-your-finger-at-the-boys song. B+