By Michelle Nichols

NEW YORK (Reuters) - After learning she had won the Nobel Peace Prize on Friday, the first person Liberian Leymah Gbowee shared her joy with was a complete stranger sitting next to her on a flight that had just landed in New York City.

Gbowee, who is in New York to promote her memoir "Mighty Be Our Powers," started crying when she turned on her cellphone after the flight from San Francisco landed and read a text message from a friend that simply said "Nobel, Nobel, Nobel."

"The thing is when you have good news you want to share it with someone. The guy who sat next to me on the five-hour flight, we never spoke to each other, but I had to tap him and say 'Sir, I just won the Nobel,'" Gbowee, 39, told Reuters.

Gbowee, who promoted a "sex strike" among efforts to end Liberia's civil war, shared the prize with Liberian President Ellen Johnson-Sirleaf, the first woman freely elected as a head of state in Africa, and Yemen's Tawakul Karman.

The mother-of-six said that when people started telling her in the past few days that she could win the Nobel Peace Prize, she "didn't give it a second thought."

"I didn't want to be too hopeful because I felt like it's not the most important thing in the world. What I do is important with or without a Nobel Peace Prize," she said. "I'm numb, I'm fuzzy, I'm overwhelmed and all I keep hearing in my head is the song of Praise to God."

"I will still do what I do because I am a symbol of hope in my community, on the continent, in a place where there is little to be hopeful for," she said. "If you are a symbol of hope you don't do it because you are expecting a reward, you do it because you are expected to do so."

RE-ENERGIZED BY AWARD

Gbowee's Women For Peace movement is credited by some for helping end the 1989-2003 civil war. Starting with prayers and songs at a fish market, she also urged the wives and girlfriends of leaders of the warring factions to deny them sex until they laid down their arms.

She is the subject of an award-winning documentary film "Pray the Devil Back to Hell," which documents the story of the female peace activists in Liberia who helped end the war in which more than 200,000 people were killed.

The campaign culminated in the election of Johnson-Sirleaf, who is seeking a second term in office in election on Tuesday. Gbowee is due to leave New York later on Friday to return to Liberia so she can vote.

"This is a major boost for her campaign. The prize to her, to me, is a recognition that the women of Liberia have done great and that she deserves to move on with her development agenda," Gbowee said.

"For me going forward the loud statement that has been made with this award is that the plight of women, the role of women, the involvement of women, their needs and priorities will never be ignored in this world," she said.

The Nobel committee said the three winners were rewarded from the bequest left by Swedish dynamite inventor Alfred Nobel for "their non-violent struggle for the safety of women and for women's rights to full participation in peace-building work".

Gbowee said she had been re-energized by her Nobel Peace Prize win and would make the most of the global platform she had now been given for her cause.

"I will continue to do what I know to do best," Gbowee said. "Advocating for the rights of women, advocating for their involvement in peace and security and advocating for a peaceful world ... that's what I feel God has called me to do."

(Editing by Mohammad Zargham)