October 26, 1862.
I cannot express the anguish I feel at the death of our sweet Annie. To know that I shall never see her again on earth, that her place in our circle, which I always hoped one day to enjoy, is forever vacant, is agonizing in the extreme. But God in this, as in all things, has mingled mercy with the blow in selecting that one best prepared to leave us. May you be able to join me in saying, "His will be done!" When I reflect on all she will escape in life, brief and painful at the best, and all we may hope she will enjoy with her sainted grandmother, I cannot wish her back. I know how much you will grieve, and how much she will be mourned. I wish I could give you any comfort, but beyond our hope in the great mercy of God, and the belief that He takes her at the time and place when it is best for her to go, there is none. May that same mercy be extended to us all, and may we be prepared for his summons.
SOURCE: John William Jones, Life and Letters of Robert Edward Lee: Soldier and Man, p. 198-9