Muggles' Guide to Harry Potter/Characters/Auntie Muriel

Overview
Ron's Auntie Muriel (no mention whether she's a Weasley or a Prewett, though her opinions suggest she is a Prewett) is an aged, outspoken, eccentric relative of the Weasley family.

Half-Blood Prince
Fleur Delacour and Bill Weasley are engaged, but Bill has just received dreadful wounds from Fenrir Greyback that are unlikely to ever heal. Molly Weasley, tending his injuries, laments that the wedding is now not going to happen. Fleur, outraged, says that the wedding most certainly is going to happen, and pushes Molly aside to take over tending Bill's wounds. Briefly stunned, Molly tells Fleur that Auntie Muriel has a goblin-made tiara that would look good in Fleur's hair, and says she'll see if she can convince Muriel to loan it to her. Fleur accepts. This marks the reconciliation between the two women.

Deathly Hallows
As the seven Harry Potters escape from Privet Drive, each Potter and protector pair is destined for a different safe house. Ron and Tonks are destined for Auntie Muriel's. Muriel keeps them busy for so long after they arrive that they miss their Portkey, and there is a great deal of worry at the Weasley house until they finally arrive on Tonks' broom.

Auntie Muriel is one of the wedding guests, who expects preferential treatment because, "I'm a hundred and seven." She arrives on Ron's arm, criticizing the length of his hair – she claims that for a moment she had mistaken him for Ginevra. She briefly accuses Ron of lying about knowing Harry Potter when Ron says he has made his excuses – Harry is present, but in disguise. Ron takes her, still grumbling, to her seat, where she evidently keeps him occupied for some time.

After the ceremony, during the music afterwards, Harry is speaking with Elphias Doge about the eulogy he had written for Albus Dumbledore, and the muck-raking book that Rita Skeeter had written on the same subject. Auntie Muriel, passing by, hears the conversation and joins it, saying that she couldn't wait to read Skeeter's book, she reads everything she writes. She goes on to say that she believes that Dumbledore had practiced Dark magic as a youth, and that his sister Ariana was most likely a Squib. She claims that Ariana had been locked up, as it was taken to be a disgrace to have produced a Squib, and so it was common practice in those days to try to hide the child, integrating him or her with Muggles. In response to Elphias' protests, she says that Ariana couldn't have been sickly, because her cousin Launcelot was a healer at St. Mungo's, and Ariana had never been there. She goes on to say that she believes that Rita's source was Bathilda Bagshot, and that she was likely still alive, and still living in Godric's Hollow, where the Dumbledores had lived as well. Harry, taken quite by surprise by this last revelation, wonders why Professor Dumbledore had never told him of this connection.

Auntie Muriel's stream of revelations is broken by the announcement that the Ministry has fallen and Rufus Scrimgeour has been killed. This effectively ends the wedding party, and Harry, Hermione, and Ron depart.

Much later, when Harry, Ron, and Hermione are recovering at Shell Cottage, they learn that several of the Weasley clan are now living in Aunt Muriel's house. Apparently, Fred and George are attempting to run Weasleys' Wizard Wheezes by mail order out of one of her back bedrooms. When Ollivander is taken to her house by Bill Weasley, Fleur asks him to carry the tiara that she had worn at the wedding back to Auntie Muriel.

Relationships with Other Characters
Auntie Muriel is an incurable gossip, in some ways as bad as Rita Skeeter, of whom she is a great fan. She never hesitates to make use of her age to claim preferential treatment. She disapproves of Hermione, and has said that Weasleys breed like gnomes.

It is also stated by Ginny that Ron keeps a picture of Aunt Muriel under his pillow, who he kisses before he goes to sleep each night. However, this was said during a fight, and is most likely untrue.