She married religious and political reformer John Jebb in 1764 and fully shared his ideals.

When they were first married he was lecturing at Cambridge, and she developed a reputation of her own in university circles where she held gatherings for reformers.

[1] Her writing often took the form of letters, signed with the nom de plume "Priscilla", such as the series she wrote to the London Chronicle (1772–4) during the movement of 1771 to abolish university and clerical subscription to the Thirty-nine Articles.

Subsequently, in 1775, John Jebb resigned his church living, with the full support of Ann; John studied medicine and the couple later moved to London, where they were involved with a number of reformist causes such as the expansion of the franchise, opposition to the war with America, support for the French Revolution, abolitionism, and an end to legal discrimination against Roman Catholics.

[1] Her writing appeared in the London Chronicle, the Whitehall Evening Post and the Monthly Repository, as well as in pamphlets and tracts.