True Blood actress Adina Porter has been promoted to series regular status for the vampire show's seventh and final season.

Porter - who plays Tara's (Rutina Wesley) mother Lettie Mae Thornton - will be a series regular for the final season according to The Hollywood Reporter. Porter has been on True Blood since the first season but has been billed as a special guest star since season 2.

Porter last appeared as Lettie Mae in the season 6 finale, in which the character reconciled with Tara. She offered to feed her daughter her blood to make up for her past actions and Tara eventually accepted.

With Porter being promoted to series regular status, it can be assumed that Lettie Mae will be an important character in the final season. Porter officially joins a main cast that is already large and expanding.

True Blood Final Season: Carrie Preston Says Arlene Shouldn't Be 'Paired Up With Somebody' 

In other True Blood news, actor Luke Grimes has signed on to appear in the highly anticipated Fifty Shades of Grey movie. Grimes - who plays Jessica's (Deborah Ann Woll) love interest James - will be appearing in the adaptation of the erotic novel.

Grimes is only a member of the guest cast but the news of him being cast in Fifty Shades of Grey could influence his availability in the final season of True Blood. His character James was last seen in the finale playing volleyball and appearing at a human-vampire social.

True Blood: The Movie? 

True Blood's seventh and final season will air in summer 2014 though HBO has not scheduled a premiere date yet.