Lily being spared

[pippin_999]

No: HPFGUIDX 189847


 June:
According to Dumbledore it was either Harry or
> > Neville and Voldemort would be the one to decide, therefore if
> > he had gone after Neville and not Harry, Neville would have
> > been the boy who lived. Therefore I cannot see how Snape's love
> > for Lily would have anything to do with it. Snape's love for
> > Lily is just part of the theme which is love conquers all.
> > 
> > 
> Potioncat:
> DD has a way of only telling a part of the truth. From his standpoint both boys fit the description. I'm not sure if DD really thinks Neville would fit the prophecy or if he just means both boys fit the description.
> 
> But what if LV had chosen Neville? Alice would have died. Neville would have died.  LV would have been just fine. His soul would be a tad more ripped--and after a while (moments or weeks or years) he would begin to wonder if he had chosen wrong. He would have gone after the Potter boy too.

Pippin:
But what if Lily had already died, or was out visiting Bathilda when Voldemort arrived? Then the prophecy would have been fulfilled but the one who could vanquish Voldemort would have died at his hands. 

To me the interplay between  Lily's magic and choice is comparable to mixing potions. Potions need a witch or wizard (according to JKR) but they may also need  non-magical ingredients like lacewing flies. Choice in itself is not magical, and indeed some very significant choices in the books are made by Muggles. But Lily's magic would not have worked without the element of choice.

Pippin