Below is a round-up of the birth announcements from British newspapers. Sources include a national paper (The Telegraph, The Times) and a broad range of local newspapers from across England, Wales, Scotland and Northern Ireland.
Sibling names are in brackets. No official surnames are included; any name ending in a surname is actually a middle name.
Boys:
Douglas Walter (Stanley Peter)
Felix Laurence (Jack & Matilda)
Frederick Peter Ceri
Freddie
Henry Nicholas Godfrey
Lawrence
Montague Neil (Anya)
Quentin Jack (Ruaridh Pierre)
Ruán Eddie
Saran Singh (Shaan)
Spencer
William Alexander
Girls:
Eleanor Sophie Joanna
Emily Catherine Jane
Emily Victoria
Florence Cooper
Indigo Annie Rose (Toby & Lennox)
Isabella Anne "Bella" - Grandmothers are Isabelle and Anne
Isabella Rose Nilima
Leela Siena
Matilda Lucinda
Molly Samantha
Ottilie Catherine
I cross-reference older BAs to find the full names of the siblings, however often they are missing (especially the eldest siblings, or for half-siblings) which explains why you will sometimes see something like: George Henry (Lucy, Emma & Jack Arthur). "Lucy" and "Emma" may well have middle names as well; I simply cannot find them online.