During the Battle of Beauharnois, she, her husband, and her sister – along with the general household – were taken by surprise during a nighttime siege led by François-Marie-Thomas Chevalier de Lorimier, then held as prisoners.
Her husband was held separately.
She negotiated with the rebels, and they were allowed to remove to the home of the Catholic priest, then allowed to obtain meat and milk from the Ellice's livestock, to sustain the, eventually, 62 people sequestered together in what she described as the Ellice house "converted into a regular prison."

“A brisk firing commenced all around the cottage; bullets coming through the house in all directions.
Then came a dreadful rush of Men, women & children, screaming, some falling & being trampled upon in the door way.
We thought the rebels were coming to murder us, & locked in Tina's arms I was trying to compose my mind when Mr. Parker pushed thro' the crowd & told us we were safe.”

— Jane Ellice, The Diary of Jane Ellice
That day, 10 November 1838, the British won the battle, rebel leaders were taken prisoner, and the Loyalist prisoners were freed.
Mrs. Ellice had written a diary and made sketches of the "picturesque ruffians."
Lord Durham had resigned 9 October 1838, and returned to England, which the Ellice household had been scheduled to do on 9 November, but were then captives.
They then returned to England on 26 December 1838.
During the Battle of Beauharnois, she, her husband, and her sister – along with the general household – were taken by surprise during a nighttime siege led by François-Marie-Thomas Chevalier de Lorimier, then held as prisoners. Her husband was held separately. She negotiated with the rebels, and they were allowed to remove to the home of the Catholic priest, then allowed to obtain meat and milk from the Ellice's livestock, to sustain the, eventually, 62 people sequestered together in what she described as the Ellice house "converted into a regular prison."
“A brisk firing commenced all around the cottage; bullets coming through the house in all directions. Then came a dreadful rush of Men, women & children, screaming, some falling & being trampled upon in the door way. We thought the rebels were coming to murder us, & locked in Tina's arms I was trying to compose my mind when Mr. Parker pushed thro' the crowd & told us we were safe.”
— Jane Ellice, The Diary of Jane Ellice
That day, 10 November 1838, the British won the battle, rebel leaders were taken prisoner, and the Loyalist prisoners were freed. Mrs. Ellice had written a diary and made sketches of the "picturesque ruffians." Lord Durham had resigned 9 October 1838, and returned to England, which the Ellice household had been scheduled to do on 9 November, but were then captives. They then returned to England on 26 December 1838.
Katherine Ellice