Her father died in 1687 and was succeeded by her half-brother Richard as the 8thEarl of Clanricarde. Honora inherited a fortune of £3,500 from her father. Her mother married thirdly, sometime between 1687 and 1700, to Colonel Thomas Burke. The marriage seems to have been childless.
First marriage
On 9 January 1689 Honora married Patrick Sarsfield in Portumna Abbey. The couple went to live is Sarsfield's house at Lucan near Dublin. Sarsfield was at that time the eldest living son of a landowner from County Kildare and an experienced soldier, serving in the Irish Army of James II during the Williamite War in Ireland. Sarsfield rose rapidly to become one of the leaders of the Jacobite movement in Ireland, noted in particular for the Ballyneety Raid on King William's artillery train shortly before the Siege of Limerick. In January 1691 James II ennobled him for this achievement making him the 1st Earl of Lucan. She therefore became Countess of Lucan. After the surrender of Limerick following a second siege in 1691, Sarsfield led the defeated Irish Army to France to continue serving the exiled James II, an event known as the Flight of the Wild Geese. Honora had probably left for France a year earlier with other Jacobite ladies. In 1692 he participated in a failed plan to invade England. On 29 July 1693 Sarsfield was mortally wounded at the Battle of Landen and died shortly afterwards at Huy. Her marriage with Sarsfield produced two children:
James, who became the 2nd Earl of Lucan and took part in the planned 1719 Jacobite Rising in Ireland, but died of natural causes shortly afterwards.
A daughter, probably called Catherine, as she has been confused with Catalina Sarsfield.
It is occasionally suggested that the Catalina Sarsfield who married a German adventurer who briefly established himself as King Theodore of Corsica, was a daughter of Honora and her first husband. In fact Catalina came from a different branch of the Sarsfield family, from County Limerick and was born in Nantes to David Sarsfield, a distant cousin of Patrick.
Second marriage
The widowed Honora, now living at the Jacobite court-in-exile at Saint-Germain near Paris, met James FitzJames, 1st Duke of Berwick and fell in love with him. Berwick was the illegitimate son of James II and Arabella Churchill, and took up a military career at an early age. He had served alongside Sarsfield in Ireland. They married on 26 March 1695 in the chapel of the Château de Saint-Germain-en-Laye. making her the Duchess of Berwick. The King was not overjoyed at the marriage, as he had wanted his son to make a grander match that might help the Jacobite cause. In that same year her husband was attainted in England and therefore lost, at least officially, his title. However, she and her husband continued to use the title and were generally known as the Duke and Duchess of Berwick. Saint-Simon, for example calls him so in 1698. With Berwick she produced a son:
James, who served in the Spanish Army and founded a dynasty in that country.
Death and timeline
She died at the age of twenty-four on 16 January 1698 of consumption, leaving her husband in "great grief". She was buried in Pontoise.