Eileen Prince

Eileen Snape (née Prince) was a witch. She was married to Tobias Snape, a Muggle, and was mother to Severus Snape.

Early life
Eileen Prince was born into a Pure-blood wizarding family. According to an old Daily Prophet clipping found by Hermione Granger, during her fifth year at Hogwarts School of Witchcraft and Wizardry, Eileen Prince was captain of the school Gobstones Team. It is unknown exactly when Eileen began attending Hogwarts, but, based on the description of a copy of the sixth-year Potions textbook Advanced Potion Making owned by her son as being "nearly fifty years old" in December 1996, it is possible that she started sometime in the early 1940s, if the book was bought new and then handed down. The House into which she was sorted is also unknown, although, given her son's desire to be sorted into Slytherin, it is possible she was one herself, or that Slytherin was the traditional house of the Prince family.

Family
Eileen married Tobias Snape, a Muggle, and lived with him in a row house on Spinner's End. On January 9, 1960, she gave birth to a son, Severus. Life in the Snape home was tumultuous, as Severus informed his friend, Lily Evans, that his parents were constantly arguing. Tobias seems to have been aware of the fact that Eileen was a witch, having been described by his son as not liking anything, least of all magic. Eileen accompanied her 11-year-old son to Platform 9¾ for the first time on September 1, 1971, an event later watched in a Pensieve by Harry Potter.

Physical description
At age 15, Eileen is described as having been thin, pale, and sullen-looking, with a long face and thick eyebrows. In 1971, as an adult woman, she was thin, sallow, and sour-looking, bearing a strong resemblance to her son.

Trivia

 * Severus Snape took his nickname, the Half-Blood Prince, from his mother's maiden name combined with his own blood status of half-blood.
 * When Harry Potter entered Snape's mind using Legilimency, he saw a man shouting at a woman, and a boy (Snape) crying in a corner. The woman was presumably Eileen.
 * Irma Pince has been rumoured to be Eileen in hiding, due to the fact that the letters in Pince's name can be rearranged to spell "I'm a Prince," but this has not been confirmed.