Tonks, as she is known, is the daughter of Andromeda Black and Ted Tonks. She is a Half-Blood, but both of her parents are actually magical. Her mother is a pureblood, and her father is a muggle born, therefore considering that the majority of her father's family are muggles she is considered a half-blood, even though he is not a muggle himself. Tonks is a metamorphmagus, which means that she can change her appearance at will.
Tonks is first described in the books as having a pale heart-shaped face, dark twinkling eyes, and short, spikey hair that was a violent shade of violet. She knocked over a plate in the Dursley's kitchen when the 'Advance Guard' came to pick up Harry to take to number twelve, Grimmauld Place. She also knocked over the troll umbrella stand, which made Sirius's mother start screaming. She is known as "seriously clumsy."
Nymphadora was born on the 11th of May, 1973. She attended Hogwarts School of Witchcraft and Wizardry from 1984-1991, the time of Charlie Weasley, and was Sorted into Hufflepuff House. She never became a Prefect in her 5th year, because her Head of House, Podoma Sprout, said she lacked necessary qualities, such as the ability to behave herself.
She works as an Auror in the Ministry of Magic under the eye of Mad-Eye Moody. She worked as a spy for the Order of the Phoenix. So did Arthur Weasley, Kingsley Shackelbolt, and a few others, as they themselves worked inside the Ministry.
In Harry Potter and the Deathly Hallows, she marries the werewolf Remus Lupin (even though she is much younger than him) and they have a son named Edward Remus 'Teddy' Lupin. He is a metamorphmagus, just like his mother, and is known for having aqua colored hair. Teddy is a metamorphmagus like Tonks. Both Tonks and Lupin die during the Battle of Hogwarts.