She is married to King Edward.
They got married on September 10, 1299 at Canterbury, Kent, England.Source 1
Edward was then 60 years old, at least 40 years older than his bride. The wedding took place at Canterbury on 10 September 1299.[5] Margaret was never crowned due to financial constraints, being the first uncrowned queen since the Conquest. This in no way lessened her dignity as the king's wife, however, for she used the royal title in her letters and documents, and appeared publicly wearing a crown even though she had not received one during a formal rite of investiture.