Andromeda Tonks was born Andromeda Black, one of the most stuffiest pureblood families that one could find around the wizarding world with the Malfoys close behind. She was the middle sister, her father's favorite, with her older sister Bellatrix nearly always picking on her. She was a bit closer to Cissy, but not by much. She was a quick learner and it was no surprise when her letter came for Hogwarts. It was also no surprise when she was placed in Slytherin, even though she wanted to be in Gryffindor with a friend she met on the train platform, Ted Tonks. There was happiness when she was made a prefect and even more so when she became head girl. It was only after school that everything went downhill because her parents wished her to marry a stuffy pureblood. Thanks to her favorite cousin, Sirius, Ted was able to come and rescue her. It was the night that he rescued her that they married and lived happily ever after. That's Andy's story and she's sticking too it when she tells her daughter Nymphadora the story when she asks for it.
Since then, she became an auror for the Ministry (and a professor at Hogwarts in another game). She's battled against prejudice for the family she had before she married Ted and the Dark Eaters that are now in hiding. Considering the unhappy alternative, she counts her blessings.