She succeeded her grandfather
John Stewart, 3rd Earl of Buchan in 1551. In that year she was the heir to her father,
enfeoffed in the lands, jurisdictions, and offices enumerated in her grandfather's charter of 1547. She was only three years of age at her mother's death, and was placed under the guardianship of
Margaret Erskine, wife of
Robert Douglas of
Lochleven. In January 1549–1550, though Christina was only a young child, a contract of marriage was arranged between her and
James Stewart, afterwards
Earl of Moray and Regent, which would give him possession of her lands. He was the son of
Margaret Erskine by
King James V. Notwithstanding this contract, he later married
Agnes Keith. Christina married Moray's half-brother, Robert Douglas, second son of Margaret Erskine and
Robert Douglas of Lochleven. In his wife's right, Robert Douglas became
Earl of Buchan and
Sheriff of Banff. In 1574, Christina Stewart and her husband obtained a charter of the family estates, heritable offices, and the Earlshill in conjunct fee, with remainder to the heirs-male of the marriage, heirs female, heirs of the body of the Countess, and finally, to the nearest lawful heirs of the Earl. Her husband, as Earl of Buchan, took a prominent part in the political movements made in the minority of
James VI, and he supported his brother Regent Moray in opposition to the adherents of Mary, Queen of Scots. After
Regent Moray's assassination in January 1570, he was one of the four lords to whom the government of the country was committed in name of the King. == Family ==