My 9 MO DD hardly naps....

It's beginning to concern me. She probably takes a 30 minute to one hour nap in the morning & maybe that long in the afternoon. Sometimes it's only one hour to hour 1/2 nap all day. She's fussy & tired by the time 7:00 comes around but I had been keeping her up 'til around 8:00 so she'd sleep longer in the morning. I know there's no exact science but I read babies her age are supposed to get 13 - 14 hours of sleep a day. If she's only getting 11 - 12 should I be worried?? I don't even know where to look for information. Or should I call her pediatrician? Actually, I was hoping to get some opinions here from other Moms first. Anyone??