The picture is clearly of one of the Herschel daughters, probably Maria Sophia who would have been 4 years old in 1843, possibly of Margaret Louisa who would have been 9. Matilda Rose, who would later marry a Hardcastle was only one at the time.

Two of the Herschel children married into the Hardcastle family, William James the Herschel's eldest son married Anne Emma Haldane Hardcastle in 1863 while Matilda Rose married Emma's nephew, Henry Hardcastle in 1865. It is unclear who exactly S. E. Hardcastle is but s/he is likely to be part of this family, part of which was based in Hawkhurst where the Herschels were living in the 1840s. All were part of a family with strong connections to the London MIssionary Society.