Renata

Renata is Aro’s personal guard. She can make anyone feel distracted and wandering when they are near her.

Sulpicia

Sulpicia is Aro’s wife. Normally she does not leave Volterra, but in Breaking Dawn she comes to Forks with the Volturi to kill Renesmee.

Sulpicia has an unkown ability.

Gianna

Is the human secretary who appears in New Moon. Despite her hopes to become a vampire, she is killed by the Volturi by the events of Breaking Dawn.

Didyme

Didyme was Aro’s sister. He changed her hoping she could have his abilities. But Didyme’s ability is to have the power to make others happy which was not interesting enough for Aro.

When Marcus fell in love with Didyme and seemed more distracted than ever Aro killed his own sister.

Chelsea

Wife of Afton and used by the Volturi to crack other covens.

Chelsea can change emotional bondings.

Athenodora

Athenodora is Caius’ wife. As the other wifes of the ancient Volturis she never takes part in fights and comes to Forks fort he only reason not to have stay home alone in Volterra.

Source:wikipedia.org