Why were women such as Sojourner Truth not fully satisfied with the Fifteenth Amendment?

The fifteenth amendment did not give women the right to vote; it prevented individuals from being prohibited to vote based on race, color, or previous condition or servitude, but not gender. Women had to wait until 1920 for the 19th amendment to be passed to get the right to vote.

It has the potential to lead to limits on rights by giving flexibility in making laws.