In respect of the two additional names either side of Barbara Esmee St. John, mentioned above, the following is information from the "Roll of Honour - Sussex - Ninfield" site which gives a bit more clarity to one of the inscribed names.
"W. Ferner - 2nd Middlesex" would appear to be Lance Serjeant William FURNER (with a 'U' and not an 'E' - which is correct ?)
FURNER William [Adimore Sussex]
Lance Sergeant L.12108, 2nd Battalion, The Middlesex Regiment. 33rd. Division Killed in action on the Chemin des Dames 27th May 1918. Aged 30. Son of James & Ellen Furner of 2, Holly Cattage, Catsfield. Enlisted in Eastbourne. Commemorated on The Soissons Memorial MR. 18
His CWGC entry is :
Date of Death:27/05/1918 Age:30
Regiment/Service:Middlesex Regiment 2nd Bn.
Panel Reference: Memorial:SOISSONS MEMORIAL
Additional Information:Son of Ellen Furner, of 2, Holly Cottage, Catsfield, Battle, Sussex, and the late James Furner.
I'm still not progressing, at the moment, with "A.H. Lemmon - East Surrey" - his entry on the "Roll of Honour - Sussex - Ninfield" site is shown as :-
LEMMON A H
E Surrey. No definite I/D with CWGC or SDGW.