"It was something I'd been dreaming of for so many years, and it was great that I was finally able to achieve it," she told Early Show co-anchor Julie Chen. "But then, in a way, I also felt like I couldn't believe it was happening."
Shivashankar, of Olathe, Kan., outlasted 11 finalists out of a record 293 entrants by correctly spelling "laodicean" Thursday night for the win.
Shivashankar told Chen she began studying for the competition by going over word lists with her father, who is also her coach. "I don't memorize these words," she said. "I study these with the roots, and using the etymology -- the language of origin -- and all the other clues to help me."
The champion said she studied in her spare time between practicing violin, Indian dance, and doing her homework.
Shivashankar has been entering spelling bees since second grade. This year was her fourth appearance at the national bee, having finishing 10th, eighth and fourth over the last three years. "I've been studying for this for a really long time," she said.
And she knew the final word right away.
"I was familiar with that word," she said. "I had studied it before, so I knew it."
Shivashankar won more than $40,000 in cash and prizes, and the huge champion's trophy.
She said on The Early Show she was going to save most of the money for college, hoping to become a neurosurgeon when she grows up.
Second place went to 12-year-old Tim Ruiter of Centreville, Va., the only non-teenager in the finals. He misspelled "maecenas," which means a cultural benefactor.