Lorraine is Vincent’s sire – the woman who turned him into a vampire. Vincent is her favorite. Who is Vincent’s favorite? That is revealed in the series.
From Inside the Grey House:
“Lorraine. There are things we must discuss.” This was coming from an older vampire, one Vincent recognized.
Her voice was kinder when talking to this one. “Rowland, please, I know your grievances. I can address them tomorrow. Vincent is here for one night, and as I told you when he called, I will have my fun with him. It’s been a long time since I’ve seen him, and I don’t want to argue about it. Go about your duties and I’ll see you again tomorrow night after he leaves.”
Rowland seemed to shrink back into himself, unhappy with the situation. All Lorraine’s children were aware Vincent was her favorite. All who lived near her were happier when he wasn’t around. Rowland gave Vincent a nasty look but bowed to his sire and left. Morton stayed glaring, and the third vampire left without a word. Lorraine gave Morton a tempting look as she took Vincent’s hand and led him away to her dungeon. Morton glared after them until he was led to the door by two of Lorraine’s humans.