Rachelle Andros is Alex’s Mother.
She is described to have a willowy figure, with long brown hair and vibrant green eyes. She is of similar height to her daughter, Alex.
Alexandria is Rachelle's daughter and the two had a good relationship. A week prior to Half-Blood, Rachelle was attacked in Miami, which led to the belief she was dead by Alex. Later in the series, Alexandria finds out that Rachelle isn't dead, but had been turned into a daimon. Alexandria sets out with Caleb to go and kill Rachelle in Pure and succeeded.
Lucian is the husband of Rachelle, and step-father of Alex. Lucian and Rachelle got paired up together since they were both pures. Even though Rachelle was in love with Alexander Andros, she married pure-blood Lucian.
Alexander Andros is the father of Alexandria Andros. Rachelle met Alexander when they were young, and had Alexandria even though it was forbidden for half bloods and pure bloods to have a relationship. Because of this, Alexander was sent to be a servant and Rachelle married Lucian some time later, believing that Alexander was dead. Alexandria was named after him.