She was born in England, the daughter of Robert Hobart (later the 4th Earl of Buckinghamshire) and his wife Margaretta (née Bourke).

[2] On 1 September 1814, she married Frederick J. Robinson, who was then MP for Ripon and held the position of Paymaster of the Forces in the cabinet of Lord Liverpool (Prime Minister 1812–27).

There exist letters written by Sarah's step aunt, the writer Emily Eden, which frequently describes her niece's strange behaviour.

After he resigned as Prime Minister in January 1828, one of his colleagues remarked that he was "quite another man who sleeps at nights now, and laughs and talks as usual".

[10] Lady Sarah arranged that all the local children could attend school for a penny a week, paying the difference herself.

"[12] In 1862, Countess had the church of All Saints in Nocton Hall torn down and rebuilt in memory of her husband, to a design by George Gilbert Scott.