Mafalda's mother is a character that was cut out of the Harry Potter book series.
She was supposed to be a Muggle and the wife of Molly Weasley's estranged second cousin. They had a daughter together, Mafalda who they found out was a witch. They asked Arthur and Molly Weasley to help introduce her to the wizarding world. Arthur and Molly took Mafalda in during the summer of 1994 but thought that her parents only wanted to get rid of her because she wasn't a very nice girl.[1]