How did Mary queen o scotts come to power?

Mary, Queen of Scots, came to power through her claim as the legitimate heir to the Scottish throne, being the granddaughter of Henry VII of England. She ascended the Scottish throne in 1542, following the death of her father, James V. After spending her early years in France and marrying the French Dauphin, she returned to Scotland in 1561 as a widow, where she aimed to strengthen her rule amid political and religious turmoil. Her reign was marked by conflict with Protestant factions and her cousin, Elizabeth I of England, ultimately leading to her downfall.