About:

Minerva McGonagall was born on 4 October, to Robert McGonagall, a Muggle Presbyterian minister, and his wife Isobel Ross, a witch. She was the couple's first child and was named after her mother's grandmother, a very powerful witch. By then, her parents lived on the outskirts of Caithness in the Scottish Highlands, in a village where mostly lived Muggles.
Professor Minerva McGonagall, O.M. (First Class), was a Scottish half-blood witch, the only daughter of Muggle Robert McGonagall and witch Isobel Ross. She also was the older sister of Malcolm and Robert Jr. Minerva attended Hogwarts School of Witchcraft and Wizardry and was Sorted into Gryffindor House, but it took the Sorting Hat five and a half minutes to decide if she was Gryffindor or Ravenclaw, which made her a Hatstall. During her seventh year, she was appointed Head Girl.
After her education, Minerva worked for two years at the Ministry of Magic and later returned to Hogwarts, where she became Head of Gryffindor House and the Transfiguration professor. Though she wasn't a member of the Order of the Phoenix during the First Wizarding War, Minerva greatly helped the Ministry of Magic's resistance through spying Death Eaters and bringing the Aurors crucial information on their activities.
Eventually, Minerva became concurrently, at differing times, Deputy Headmistress and Headmistress of Hogwarts. In 1995, she opposed Dolores Umbridge, the High Inquisitor of Hogwarts. She also protected the students from Alecto and Amycus Carrow from 1997 until 1998. As part of the Order of Phoenix's new resistance movement, Minerva fought in several battles of both wars, including the Battle of the Astronomy Tower and the Battle of Hogwarts, where she led the resistance against Lord Voldemort.
Minerva survived the Second Wizarding War and continued her job as Headmistress, a title she still held as of Albus Potter's time at Hogwarts.
During his second rise to power, Minerva joined the Order of the Phoenix and stayed in Hogwarts during the tenure of Severus Snape as Headmaster and the Carrows to protect her students. In spite of her well-known loyalty to Professor Dumbledore, Voldemort and his followers believed that Minerva was both too gifted to lose, and too sensible not to join them fully once their victory was assured. However, she proved him wrong when she defended the school against his army and, along with Kingsley Shacklebolt and Horace Slughorn, bravely duelled Voldemort himself during the second part of the Battle of Hogwarts. She watched as Voldemort is defeated by Harry Potter once and for all finally ending the War.