Aro volturi's twin daughters ( a demetri and Alec story )

Katherine and alexandria are the daughters of Aro the leader of the volturi. there mother was Hayley cauis's best friend.the twin don't know how there parents are cause the twins was sent away. and the reason for that is a newborn army was created to kill them and the volturi by a woman my Brennan. she created the army because Aro had killed her mate and won't revenge. the twins went to a orphanage and got adopted by the swans. where they were raised as one of there on but know they are all grown up they live on there on. so now what happens when they get a phone call from bella asked for help because a newborn army is coming after her. and what will also happen when they meet there mates..