This was particularly evident shortly after Sybil's birth in June 1880, when Lord Rosebery wished to visit Germany for three months to take a cure at a German spa for what is now thought to have been a nervous breakdown.

[8] She had one son, Charles Robert Archibald Grant, who married Pamela Wellesley (born 1912), a granddaughter of Arthur, 4th Duke of Wellington.

In 1912, Lady Sybil Grant published several short stories in the London Magazine, including The Kisses That Never Were Given, A Three-Cornered Secret, and Travesty.

In 1914, by now considered a literary figure, she was invited to contribute to Princess Mary's Gift Book, a collection of illustrated stories assembled to raise money for the Great War effort.

Lady Sybil was a patriotic admirer of the achievements of Marshal Foch, writing in a eulogy of him in 1929 that "the first impression you received was of an infinite horizon–he seemed to look beyond the common limits of human sight.

[13] In 1937, Grant befriended the Roma who regularly visited Epsom Downs during the Derby week, dressing herself in "unusual and romantic clothes.

With the Reverend Edward Dorling she was a leading supporter of the "Lest We Forget" charitable fund,[15] and on the charity's behalf she organised a fete in the grounds of The Durdans each year; here her pottery was often sold and in great demand.