Foster-Fulton was born and raised in South Carolina, United States.
She was minister of Camelon Irving Parish Church for four years, before serving as co-pastor of the PCUSA congregation in Seneca, South Carolina, alongside her husband, Stuart Fulton.
[2][3] After returning to Scotland in 2007, Foster-Fulton became associate minister at Dunblane Cathedral, where she served for ten years.
She described herself as "beyond humbled, inexpressibly honoured and more than a wee bit excited" to be taking up the role.
[5] On 5 July 2023, and in her role as Moderator of the Church of Scotland, Foster-Fulton gave a homily at the Service of Thanksgiving and Dedication held at Edinburgh's St Giles' Cathedral for the Presentation of the Royal Honours of Scotland to King Charles III.