It's no so much an overlap between the two movements, but rather that the Women's Rights Movement originated from the Anti-Slavery Movement or Abolitionism. Many of the women who later were part of the Women's Rights movement started the fight for social justice for slaves and were originally part of the abolitionist movement. They learned the skills necessary for successful organization of civil movements through this involvement. However, over time they realized that many of the male supporters of the abolitionist movement wanted to keep women out of it and did not support women's rights.
This difference of opinion led to the split of the American Anti-Slavery Society in 1840, when the Grimke Sisters from South Carolina were told not to organize and speak at Anti-Slavery meetings as it was "unladylike."
Another example is the Seneca Falls Convention in 1848. Two leaders from the abolitionist movement, Elizabeth Cady Stanton and Lucretia Mott, traveled to London to attend the first World's Anti-Slavery Convention in 1840. At the convention, the proposal for women's participation in the convention was rebuffed after a day's discussion. As a result, Mott and Stanton were allowed to attend the convention, but were denied the right to speak or vote. Mott and Stanton organized their own convention at Seneca Falls, New York in 1848 as the first were women's rights convention.
William Lloyd Garrison, a prominent abolitionist and founder of the American Anti-Slavery Society, was a supporter of women's rights and used his newspaper "The Liberator" to support the cause. When he saw the efforts made by many members of the American Anti-Slavery Society to exclude women, he left to form The Friends of Universal Reform in 1840. In fact, another faction left the society to form the Liberty Party.
Thus, we can conclude that the Women's Rights Movement grew out of the Abolitionist Movement.