At 18 Martha married Daniel Parke Custis, who was two decades older then her. They had four children together, two of which died in childhood. Daniel died in 1757, which left Martha rich widow, giving her control over her dower inheritance and trustee control over the children's inheritance. Very unusual for that time.
At age 27, Martha married George Washington on 6 Jan 1759. John and Martha did not have any children together, but they did raise her two children from Daniel together. They also raised Martha's grandchildren from her son, after his death. Even though Martha and George had no children together, many children called Mount Vernon home. According to our tour guide, many descendants of these children still come back to visit the home.
In the will of General Washington, at Martha's death their slaves were to be freed. He did not want to see the slave families split up. Martha freed her slaves on 1 Jan 1801.