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:
Alexander Rupert Victor
Buddy Arthur Joseph
Frederick Oliver
Freddie Brockbank
Joshua Steven Edmund
Kenji Zac (Kai)
Leo Frederick
Lewis
Magnus Alexander (Frederick James)
Maximilian William Wynn
Mikey Bruce (James Scott Douglas)
Oliver Denis
Oscar Robert Charles
Samuil Kalev (Emiliya)
Thomas Crispin "Tommy"
Girls:
Aila Judee
Arianwen Aerona
Charlotte Emily
Charlotte Ottilie Natalie (Persephone)
Chloe Rose Sullivan
Edith Lois (Remy Peter)
Eliza Hilary
Elizabeth Christine Ann
Emily Leila (Freya Alexandra)
Frida Cecily Alexandra
Gabriella Alexandra Nesta "Bunny"
Isabella Fifi Pixie
Ishbel Hester Elizabeth Sinclair Abraham Britton McLay Jackson (Hector Andrew Anthony Halsall Cowan Jackson)
June Alma Sophie (Maxi)
Juno Matilda
Matilda Grace "Stevie" (Bobbie)
Myiah Bea (Lilah Blu)
Pandora Rose (Matilda)
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.