|Muggles' Guide to Harry Potter - Character|
Madam Rosmerta is "a curvy sort of woman with a pretty face", the owner of The Three Broomsticks pub in Hogsmeade.
Role in the BooksEdit
Madam Rosmerta is first mentioned by name when Harry escapes from Hogwarts to join Ron and Hermione in Hogsmeade. Here, she acts as a foil: the adults who are in the know are filling her in on why there are Dementors floating around the village and ruining her business, and Harry is listening in. This allows Harry to receive the understood back-story about Sirius Black.
Perhaps curiously, we do not see Madam Rosmerta in the Three Broomsticks when Harry is there being interviewed by Rita Skeeter. As Harry is then banned from all further Hogsmeade weekends by Umbridge, we do not see Madam Rosmerta in this book.
Rosmerta greets Harry and Dumbledore when they secretly left Hogwarts to find Voldemort's Horcrux. On their return, she warns them of the Dark Mark above Hogwarts, and loans them brooms to speed their return to the school. At the school, Harry is present, though immobilized and concealed by his Invisibility Cloak, as Dumbledore engages Draco Malfoy in conversation to attempt to win his allegiance. In the course of conversation, Dumbledore wonders how Draco knew when they left the castle, and then realizes that Rosmerta, under the Imperius curse, had told him. This revelation also explains how Katie Bell came to be carrying the cursed necklace back to school after a Hogsmeade visit; Rosmerta, acting under Malfoy's curse, had met Katie in the toilets, placed her under the Imperius curse, and given her the necklace to deliver to Dumbledore.
Relationships with Other CharactersEdit
Ron seems to have a bit of a crush on Madam Rosmerta; perhaps he just likes her shape. He is well aware that she is literally old enough to be his mother; in fact, Madam Rosmerta was tending bar at the Three Broomsticks when Harry's father was at Hogwarts.
One of the things that goes past without significant mention is that Rosmerta is quite literally old enough to be Ron's mother, and he would realize that if he ever thought about it. Rosmerta mentions that she had known Harry's father and the other Marauders, in Harry Potter and the Prisoner of Azkaban. It is unlikely she would remember them so well if she was significantly younger than them, so we can assume that she is roughly of an age, at least, as Harry's parents, or older if, as is suggested in the discussion with Fudge in the Three Broomsticks just before Christmas, she served them in the pub. Ron still seems to be angling for a glimpse of her in subsequent books, despite the conversation having happened in his hearing, and while he was paying attention to it.