Why Lily didn't have to die

[Tonks]

No: HPFGUIDX 137604

I am beginning to think that Lily did not have to die because she was 
a potions master in the same class as Flamel.  Maybe LV had a lab set 
up with Snape and he wanted/needed someone else to help with the 
experiments.  This is sort of like RL when the enemy kidnaps the best 
scientist to make the better weapon.  In this case LV may have wanted 
them to work on making the philosopher's stone.  He could then use 
that as a the ultimate Horcrox. 

What do you all think?

Tonks_op