KILL THEM ALL.

                " Never used an Unforgivable Curse before, have you, boy? You need to mean them, Potter. You need to really want to cause pain — to enjoy it — righteous anger won't hurt me for long — I'll SHOW you how it is done, shall I? I'll give you a lesson — CRUCIO ! "

( DEFECTION VERSE. ) i am now fallen ; stardust envelops me.

in this verse bella has decided to defect during the early years of her death-eater career. she finds out that voldemort ( this is always canon to my own portrayal of voldemort and other writers shouldn’t feel pressured to adjust their portrayal for this if it doesn’t work out! ) has been poisoning her over the years, causing her to either not conceive or miscarry, a source of great grief for her, as you may know if you’ve been following me over the years ( he believed he could not lose one of his greatest assets to motherhood, as he’d been warned he might ). she learns about this and his lack of remorse and defects with the idea of carrying out vengeance. 

based on writing partners and circumstances she:

joins the order ( she has insider information and is a very talented witch to have on your side ), which will also force her to work alongside all the types of people that she would condemn before, allowing her to develop understanding and perhaps become a better person.