Melania Ismenis Macmillan (1902-2014) was the oldest daughter of Melquiades and Sigrid Macmillan, and the sister of Eligius Macmillan. She was raised in Scotland alongside her uncles and cousin. She was sorted into Ravenclaw once she started at Hogwarts, where she discovered her interest in transformations, concretely the transfigurations of furniture.
At 18 she married Arcturus Black III, the young heir of the House of Black, and a year after they had their first daughter: Lucretia. After that they decided to wait a few years to have another child, since they didn't need to have any more yet. Melania started studying transfigurations and worked for other pureblood families to enhance the looks of their homes using a few methods she invented.
When she was 26 she had her second child, Orion, with whom she had a really strong connection since the beginning. As her children grew up, the pressure of the family to marry them off incremented. Lucretia decided to marry her high-school sweetheart, Ignatius Prewett, who the family didn't approve for his stance in favor of muggleborn rights. Even then she didn't get cut off because of the negative of her father to do so. She ended up having to accept the marriage of Orion with his cousin Walburga, who Melania didn't like for her difficult personality that contrasted gravely with her son's more calm demeanor.
Shortly after her son's wedding she decided to move back to Scotland with Arcturus, where he lived his last days. She lived many years more, even after the Second Wizarding War, but ended up dying of old age at 112 (which isn't that uncommon for wizards and witches).