So this is like an old fashioned sort of set up when like kids from 4 to 18 were all in the same school. There is quite a lot of sibling sets that you might want to keep a track of but it is up to you 
here we go;
Nursery (6-18mnths):
Ashley-Cooper // Malika, Taryn, Vivienne, Eden, Idalia (Siblings in Foundation, 1, 3, 5 & 7)
Beach // Maeva, Lorelei, Hazel, Quinn, Safiya (Siblings in Reception, Year 3, 6 & 9)
Baxter // Ebony, Maya, Hallie, Olive, Iris
Eastwood // Tobias, Rory, Hugo, Colby, Luke (Sibling in Reception)
Freeman // Austin, Lucas, Jack, Max, Jaedan (Sibling in Preschool)
Hodges // Zion, Keegan, Nathan, Levi, Amias
Jameson // Lennox, Poppy, Eliana, Margot, Novella
Kneale // Isaac, Syed, Ethan, Emeric, Grayson (Siblings in Foundation & Year 1)
Lester // Bonnie, Payton, Amaya, Robyn, Zoe
Perry // Otis, Kylen, Stellan, Carsten, Felix
Riggs // Fionn, Bobby, Joseph, Tristan, Leo (Twin, Siblings in Year 1 & 3)
Riggs // Freddie, Harrison, Sonny, Kai, Osian (Twin, Siblings in Year 1 & 3)
Walker // Patrick, Jenson, Harry, Milo, Casden (Siblings in Foundation, Years 1, 3, 5, 7, 9, 11 & 13)
Walsh // Melody, Orla, Farryn, Chiara, Stella
Yates // Thomas, Oscar, George, Arlo, Elijah (Sibling in Preschool)
Pre-School (18mnths - 3yrs):
Abbey // Ewan, Raphael, Rhys, Oaks, William
Allingham //
Bowman //
Bradshaw // Dylan, Austin, Henry, Louie, Robin
Donovan //
Chilton //
Freeman //
Ingram //
Knight //
Norris //
O’Brien //
Rodgers //
Tyndall //
Warner //
York //
Foundation (3 - 4yrs):
Ashley-Cooper //
Austen-Leigh //
Bowman //
Dover //
Gibson //
Gibson //
Gibson //
Hayes //
Ingram //
Jones //
Kinglake //
O’Brien //
Walker //
Warner //
Reception (4 - 5 yrs):
Ackland //
Allingham //
Beach //
Eastwood //
Eastwood //
Eastwood //
Hayward //
Jenkins //
Kenyon //
Laughton //
McHatton //
Norris //
Nunn //
Rodgers //
Young //
Year 1 (5 - 6 yrs):
Ashley-Cooper //
Austen-Leigh //
Birdsong //
Caldwell //
Gardner //
Lambert //
O’Sullivan //
Rayner //
Riggs //
Riggs //
Thorpe //
Walker //
Warner //
Young //
Year 2 (6 - 7 yrs):
Allingham //
Bell //
Edwards //
Hayes //
Kavanagh //
Kovachevski //
Lees-Milne //
McHatton //
Nunn //
Preston //
Saunders //
Simmonds //
Yeldham //
Zachry //
Year 3 (7 - 8 yrs):