“In 1846, just before he left Arlington to join General Scott’s Army of Invasion, in Mexico, Lee wrote a will which identified Nancy among his property.”
Lee had no property when he married, a fact that displeased GWP Custis.
Nancy and the other slaves at the White House Plantation listed in his 1846 will were his wife’s property. Husbands had charge of their wife’s property in that era.
“Here it must be said, that Lee’s manumitting Nancy as part of his action as executor as the Custis estate is curious. According to his will, Lee wished “Nancy and her children” “to be liberated as soon as it can be done to their advantage.” But apparently not before his death. “
It isn’t curious at all, and it is spelled out in the Freeman chapter that you linked to.
GWP Custis’ will was a contradictory mess, in one section stating that the slaves were to be freed within 5 years while in another stating that they were not to be freed until Custis’ substantial debts were paid off. Lee had to turn the will over to the courts for the legal system to determine what should be done.
“Yet, in the midst of war he decided to include Nancy—apparently his property, not Custis’s—in the emancipation of the Custis slaves. Perhaps, he just wanted to be done with it.”
Nancy came to be Lee’s responsibility through marriage. She was his wife’s property, but he was responsible for Nancy just as George Washington was for the slaves that Martha brought into their marriage.
My understanding is that he came to own Nancy through inheritance from his mother. The 4 children of Nancy have been reported as Lee’s children by some, but at this divide, I don’t think that can be sustained or denied with evidence other than hearsay testimony by persons long dead.