Jemima, William Amhurst, Louisa
Thomas and Jemima had three children just over three years:
1. Jemima Frances Sophia (born on 15 September 1813 in the Southampton suburb of Shirley1) and died 29 May 1891 at Howden Lodge, Southsea, Hampshire.2);
2. William Amherst (1814-15), who was born and died in London when he was about 6 weeks old; he was buried at St. Paul's, London.3) and
3. Louisa Elizabeth Catherine (26 December 1816–24 July 1899). She was born at Boulogne, France and died at 23 Fernlea Road, Balham, Surrey, a suburb of London. Rosa Praed was the executor of her estate valued at £4,807.354)
Given the resemblance to the portraits thought to be Eliza Prior, and to the ones below, this miniature and its copy is likely to show the young Jemima or Louisa.5)
Jemima Prior/Murray Prior
These photos are studio ones from TLM-P’s album.6) They are labelled ‘Aunt J.’ and ‘Aunt Jemima M.P’. The former has a signature on the back dated 1872; the signature ends with Prior, and is possibly JMPrior - Jemima Murray Prior?
Jemima, like her sister Louisa, remained single. She was pious and both wealthy and generous enough to leave £200 to set up a charity, ‘The Prior Gift’. This Gift contributed to the salary of the verger at the Holy Trinity Church, Shirley, Southampton, as well for an annual distribution of food tokens to 36 ‘deserving poor’.7) Faced with large scale poverty, philanthropists in the Victorian age normally restricted aid to those considered ‘deserving’, that is, poor through no fault of their own and living blameless lives. The latter requirement alone substantially reduced the call on philanthropists’ purses!
See photo taken by Andrew Darbyshire at Southampton church, Andrew Darbyshire, A Fair Slice of St Lucia, St Lucia History Group Research Paper No.8. pp.59,60. https://brisbanehistorywest.files.wordpress.com/2017/02/08-a-fair-slice-of-st-lucia-thomas-lodge-murray-prior.pdf
Louisa Prior/Murray Prior
These three photos are studio ones from TLM-P’s album, labelled ‘Aunt Louisa’ and 'Aunt Louisa M.P’.8) The second photo has the inscription on the back ‘For Morres[?] with Aunt Louisa's Love’. Judging from Louisa's large Crinoline, the photos were taken in the mid-nineteenth century.
Louisa was christened on 22 January 1817 by the Forces chaplain: this fits in with her being born in Boulogne, France.9) She was baptised again two years later at Wells cathedral.10)
In 1863, Louisa lived at 18 Oxford Terrace, St Peters, Islington, London; by 1882 (when her brother visited her) she lived in the suburb of Balham in south London.11) She apparently later lived with her sister Jemima at Howden Lodge, 14 Clarendon Road, Southsea.12)
Middle-class women were expected to play the piano and Louisa was no exception. Some of her sheet music has survived, so we can imagine her at her piano playing these Verdi variations. 
13)