1) I see no way Harry can learn horcrux magic in six hours.
2) I cannot imagine Harry using her death as a resource. For all that he talks about using all resources he can, trhat would be a bridge too far for him, I suspect.
Using her death to resurrect her might not be beyond him, though.
Though the idea has other problems (part 1, and also that Horcrux magic, as far as we know, requires you to split your own soul.)
So he would go back in time, teach her horcrux magic, and use her own death to split her own soul so that she can later be resurrected?
1) I see no way Harry can learn horcrux magic in six hours.
2) I cannot imagine Harry using her death as a resource. For all that he talks about using all resources he can, trhat would be a bridge too far for him, I suspect.
Using her death to resurrect her might not be beyond him, though.
Though the idea has other problems (part 1, and also that Horcrux magic, as far as we know, requires you to split your own soul.)
So he would go back in time, teach her horcrux magic, and use her own death to split her own soul so that she can later be resurrected?