Euphemia Potter

Mrs Potter (d. between 1975 and 1981) was a pure-blood witch. She was married to Mr Potter, with whom she had one son, James. She was the paternal grandmother of Harry Potter.

Biography
She and her husband did not become parents until later in their lives when she gave birth to her son James on 27 March, 1960. As such, James was an only child, and was doted on quite a lot.

When James's friend, Sirius Black, ran away from home at age sixteen, he found refuge in the Potter household. Mrs Potter and her husband came to regard Sirius as something of a second son. After Sirius moved into his own flat, he kept in touch with the Potters, and was always welcome to have lunch with them on Sunday.

Mrs Potter and her husband both succumbed to a fatal wizarding illness. They were elderly at the time, suggesting they might have contracted dragon pox, which is known to be especially dangerous for older wizards.

Their deaths occurred at some point between when they took in Sirius and the night of 31 October, 1981. On that fateful Hallowe'en, James and his wife Lily were murdered by Lord Voldemort, and their son Harry was sent to live with only surviving relatives.

In all likelihood, Mrs Potter never got a chance to meet her grandson, but she was probably among the relatives who Harry saw when he looked into the Mirror of Erised in 1991.

Behind the scenes

 * Charlus Potter and Dorea Black, who appear on the Black family tree, have been speculated to be James Potter's parents. The couple had one child, a son whose name has not been revealed. If Dorea was in fact James's mother, she would have been forty when he was born, which seems to align with J. K. Rowling's revelation about the age of James' parents. However, Dorea died at fifty-seven, which conflicts with Rowling's statement that James' mother was "old in wizarding terms" when she died. (J.K. Rowling, however, has said that maths is not her strong point and this could just be a mistake) . Also, when James was young, he stated that his father was in Gryffindor and he didn't mention his mother, which might be another hint, as almost all Blacks have been Slytherins. It is also possible since Dorea Black was not blasted of the tapestry for marring a potter they were not blood traitors
 * However, it is also unlikely that Dorea is James Potter's mother as James' parents took Sirius Black into their home after he ran away from his family. As Sirius' uncle Alphard was disowned for simply giving Sirius "a decent amount of gold" when he ran away, it is likely that Dorea would also have been disowned for allowing Sirius to live with them.
 * Furthermore, as Dorea's name had not been removed from the tree, if she were James' mother then his name would have been on the tree as well, even if he were burned off later for marrying a muggle-born witch. However, Sirius never makes any mention of being related to James.

Appearances

 * Harry Potter and the Philosopher's Stone
 * Harry Potter and the Order of the Phoenix

Notes and references
Mrs Potter