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:
Artie Aubrey (Isla Olivia Rosemary)
Benjamin Oscar (Catherine, Ellie & Annabel)
Felix George Fenwick
Harry Richard
Hector George de Shordiche
James Patrick
John Alexander Ian (Rupert Charles Peter)
Oliver Louis (Theodore Franz)
Reuben James
William Peter (Bertie)
William Stephen Andrew
Girls:
Cara Alex
Cara Giselle Marie
Charlotte Arabella (Archibald Francis Geoffrey & Alfred Thor Crichton)
Florence Harper (Arlo Alexander)
Grace Esmae (Ella, John & Arthur)
Lily
Margot Albertine Fiore Foster
Penelope Carly Carol (Zachary)
Twins:
Sebastian & Benedict
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.