Her parents were Frances Ann (née Hodgson) and William Delafield Arnold.
Their father died in 1859 en route in Gibraltar so they arrived in England as orphans, but they were adopted by her mother's sister Jane Martha (née Arnold) and her husband William Edward Forster.
[1] Her adoptive parents initially saw to her education before she attended a private girls' school.
Hugh became a politician and writer and her sister Florence Mary Arnold-Forster set up the Limerick Lace School.
[4] Possibly her most important work is Studies in church dedications or England's patron saints which was issued in three volumes.