I've started linking it up on the family members on my Balmer tree. It's work in progress, but thought I'd let you know straight away!
1873. Elizabeth Jane Bannister married John Harrison on 24/4/1873 in st Paul´s Church, Hampstead Hampstead Jun 1873


Her family history
https://www.ancestry.co.uk/family-tree/person/tree/41904563/person/20200223270/facts
1874.? Florence Harrison ?born . But no birth yet to be found. Could she have been born as Bannister before the marriage- cannot find this either
1881C. Waterside, Henley on Thames . A visitor with the Williams family
| John | Harrison | Visitor |
Married | Male | 52 | 1829 | Gentleman | Walsall, Staffordshire, England | |
| Elizabeth Jane | Harrison | Wife |
Married | Female | 30 | 1851 | - | City of London, Middlesex, England | |
| John William | Harrison | Son |
Single | Male | 7 | 1874 | - | Norton Hall Staffordshire, England |
and John William Harrison is registered in Bmd as born Penkridge Mar 1874, mother Bannister. Actually born on Christmas day 1873. At schoolñl in Sussex in 1891C He went to Christ´s Cambridge and was still alive in 1935. Adm. pens. at CHRIST'S, Oct. 1, 1894. S. of John (1848). B. Dec. 25, 1873, at Norton Hall, Staffs. School, Bradfield College. Matric. Michs. 1894; B.A. 1897; M.A. 1903. Of Chittington Ferrings, Lewes, Sussex, in 1935. (Bradfield Coll. Reg.; Peile, II. 793.)
A Jane Harrison is registered in Bmd as born Penkridge Jun 1873, but mother´s maiden name is Heppard!! and a Lucy Harrison is registered in Bmd as born Penkridge Sep 1875 but mother´s maiden name is Steadman!!
A Florence Harrison is registered in Bmd as born Cannock ( includes Penkridge) Mar 1878,but no mother given on FMP!! BUT, could she have married in November 1892??, aged 14-15
No Ancestry London baptism of any Harrison to John 1873-1877
Elizabeth Jane Harrison died 1890!

John Harrison dying 1905 , leacing aroun 160000 pounds to John William Harrison - from probate

So all the above Hypothesis now rejected
1891C. Likely Florence Bannister, actress, 16, b. Marylebone in Wolverhampton. . Who is Charles Bannister 1827 - Ancestry trees exist & his wife dies 1887. No birth for a Florence Bannister born Marylebone
| Charles | Bannister | Boarder | Married | Male | 64 | 1827 | Retired Solicitor | Braunton, Devon, England | |
| Jane | Bannister | Boarder | Married | Female | 43 | 1848 | Theatrical Wardrobe Mistress | Calcutta India | |
| Florence | Bannister | Boarder | Single | Female | 16 | 1875 | Actress | Marylebone, Middlesex, England | |
| Edward | Fielding | Lodger | Married | Male | 40 | 1851 | Vocalist & Comedian | Hackney, Middlesex, England | |
| Frances | Fielding | Wife | Married | Female | 38 | 1853 | Vocalist & Comedian | Finsbury, Middlesex, England |
Charles, 55, in 1881C wiith wife Jane Chappel Bannister, 54, & children Edith Maud 15 & William Walter 17. . His wife dies in 1887. . Thus the above Jane, 43, is a newwoman, and not his daughter Elizabeth Jane either
So assume Jane Unknown has just adopted the name Bannister for respectability, and her daughter Florence has done likewise
No Ancestry London baptism for a Florence born to mother Jane 1873-75. And cannot find a Jane ?? born Calcutta 1846-50
Seemingly no death on Bmd for Charles 1891-1928 . Have looked for probate too on Ancestry