|“||And that, Mary Louise, is why you've always been my favorite.||”|
After joining Julian and Lily Salvatore's Heretic family, Mary Louise grew close to Julian, besides being with Nora Hildegard, and came to think of him as a father. Julian in return grew to care about Mary Louise and eventually, his fatherly feelings of love towards Mary Louise trumped over all his other adopted Heretic "children." These two grew to care for one another as fathers and daughters would. Eventually, Julian was captured by Rayna Cruz and it can be assumed that Mary Louise was devastated to find out that Rayna had imprisoned Julian for nearly a century in her Phoenix Sword. Shortly after this, the Gemini Coven spelled Mary Louise and the rest of the Heretics into a Prison World before Mary Louise or the others could get Julian back.
Throughout The Vampire Diaries Series
In Live Through This, Mary Loiuse and the rest of the Heretics successfully resurrected Julian's soul from the Phoenix Stone, which Rayna put his soul in. The Heretics, along with Mary Louise, were overjoyed to be reunited with him.
In Hold Me, Thrill Me, Kiss Me, Kill Me, Julian, along with Lily host an anniversary party for Nora and Mary Louise. Julian convinces Mary to propose to Nora in this episode. However, when Valerie and Lily side against Julian, Nora breaks up with Mary due to her siding with Julian. This hurts Mary, but she continues to support Julian over Nora and the rest of the Heretics.
In Cold as Ice, Mary Louise sides with Julian against Valerie's story. She is the only member of the Heretics to do this. This causes a major rift in Mary's romance with Nora, who sided with Valerie and Lily. However, when both Mary Louise and Julian are caught between Salvatore cross fire, Nora comes to her aid.
In Postcards from the Edge, Mary Louise mentioned that she told Julian that she and Nora would deal with Rayna. Later on, Julian was staked by Stefan Salvatore. It is unknown if Mary Louise was aware of this.
- Mary Louise is Julian's favorite adoptive daughter out of all of his "children" with Lily Salvatore.
- Mary Louise is the only member of the Heretics who sided with Julian against Valerie and Lily's word that Julian is a monster.
- This act caused Nora and Mary Louise to break up.
- Their relationship can be seen as similar as Marcel and Davina's relationship on, The Originals.
- Marcel/Julian are both fatherly-vampire, adoptive figures to Davina/Mary Louise.
- Davina/Mary Louise both carry the witch gene and are very powerful against their enemies (even though Mary Louise is part vampire).
- It is currently unknown if Mary Louise is aware that Julian is dead.
- Mary breaks up with Nora due to siding with Julian when Nora sided with Lily and Valerie, which put them on opposite sides.