Much like her brothers, Robert and Thomas Addis, who were both to join the Society of United Irishmen, she was interested in politics and was a member of liberal intellectual circles.

He predicted her match with the barrister Robert Holmes, who she secretly married on 21 September 1799 in the Dublin Unitarian Church.

Robert Holmes attended to the Emmet family's legal affairs for a time, with the couple living with her parents at Casino, near Milltown, Dublin.

Holmes helped to raise the children of her brother Thomas Addis, after he was sent to Fort George, Highland, Scotland for his involvement with the United Irishmen.

During this time, their mother's letters to Thomas Addis note Holmes' devotion to her husband but also her delicate health and tendency towards low spirits.

In 1799 she was active, along with members of her extended family, in the movement opposed to the legislative union of Ireland with the United Kingdom.