Gbowee shared the Peace Prize with Liberian president Sirleaf and Yemeni activist Tawakkol Karman.
Speaking at the Women's Forum Global Meeting in Deauville, France, Gbowee said she was "let down by her (Sirleaf), not 100 percent but on certain issues, yes."
Gbowee, who helped get Sirleaf reelected to a second term as president, asked why Sirleaf's three sons all have lucrative positions within the Liberian government, and called on the president to remove one of her sons from his job as chairman of the state-owned National Oil Co., CNN reported.
Gbowee acknowledged Sirleaf has made progress during her time in office, reducing debt and rebuilding infrastructure after years of civil war, but if she does not "put her foot down (on corruption)... it's really going to hurt not just her but future women's leadership in Liberia," she said in an interview with CNN.
This year's Peace Prize winner will be announced Friday.
N.J. man wakes up from 10-hour sleep with knife in back
Sign language interpreter at Mandela service called out as fake on Twitter