The coronation of Robert the Bruce took place in March 1306 in defiance of the English claims of suzerainty over Scotland, and the new King Robert I sent his wife Elizabeth, with other family members, to Kildrummy Castle for safety under the protection of his brother Nigel Bruce.

After the defeat of the Scots at the Battle of Methven on 19 June 1306, the English laid siege to the castle containing the royal party. The siege finally succeeded when the English bribed a blacksmith with "all the gold he could carry" to set fire to the corn store. The victors hanged and beheaded Bruce's brother, along with all the men from the castle. They imprisoned Bruce's sister Mary and Isabel, Countess of Buchan in wooden cages erected on the walls of Berwick and Roxburgh castles, and they sent Bruce's 12-year-old daughter Marjorie Bruce to a nunnery. Due to Edward's unwillingness to anger the Earl of Ulster, Elizabeth went into house arrest in England.

Eight years later, after the Bruce had defeated the English at Bannockburn (June 1314), Elizabeth and other women of Bruce’s family (including Mary) finally walked free in exchange for captured English nobles.