EVENT 101 Female 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 2 | 1 | Gwen MACKENZIE-WILSON | 11 | | Wellingboro | 7:20.00 |
| 3 | 3 | Sian DUNLOP | 26 | | Wellingboro | 7:04.60 |
| 4 | 5 | Lucy DONNELLY | 12 | S15 | Corby | 6:49.30 |
| 5 | 4 | Elizabeth KAIRIS | 13 | | Wellingboro | 6:54.54 |
| 6 | 2 | Kaylyn PRIOR | 11 | | Corby | 7:08.94 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 7 | Ren WOOD | 11 | | Corby | 6:25.51 |
| 2 | 9 | Emma CHAMBERLAIN | 12 | | Wellingboro | 6:09.25 |
| 3 | 11 | Elsie BALDWIN | 11 | | Hinckley | 6:05.65 |
| 4 | 13 | Millie DAY | 17 | | Rushden | 5:52.35 |
| 5 | 12 | Sofia ILE | 15 | | Kettering | 5:53.99 |
| 6 | 10 | Josie TRAHEARN | 13 | | Hinckley | 6:07.94 |
| 7 | 8 | Iris SOMERVILLE | 12 | | Market Har | 6:23.03 |
| 8 | 6 | Kara HARRITY | 10 | | Melton M'bry | 6:26.50 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 15 | Uma STEPHENSON | 12 | | Market Har | 5:44.21 |
| 2 | 17 | Isabel HOLLYMAN | 20 | | Wellingboro | 5:32.50 |
| 3 | 19 | Hannah BEEBY | 15 | | Kettering | 5:27.60 |
| 4 | 21 | Harriet JENNINGS | 12 | | Market Har | 5:24.62 |
| 5 | 20 | Emma AFFLECK | 14 | | Kettering | 5:27.60 |
| 6 | 18 | Georgina BEEBY | 14 | | Kettering | 5:30.99 |
| 7 | 16 | Codie LOWE | 14 | | Corby | 5:34.80 |
| 8 | 14 | Amelie TANNER | 14 | | Corby | 5:49.99 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 23 | Edith KABERRY | 14 | | Corby | 5:19.80 |
| 2 | 25 | Jessica GILDER | 14 | | Hinckley | 5:15.62 |
| 3 | 27 | Milana MISUROVA | 16 | | Rushden | 5:11.00 |
| 4 | 29 | Nika BUHHAROVA | 15 | | Corby | 5:08.80 |
| 5 | 28 | Alexa PARKER | 16 | | Corby | 5:10.40 |
| 6 | 26 | Aaliyah BEETSON | 16 | | Wellingboro | 5:13.27 |
| 7 | 24 | Georgia PARKER | 14 | | Corby | 5:17.10 |
| 8 | 22 | Emily PRESTON | 14 | | Market Har | 5:22.46 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 31 | Abigail TOMLINSON | 12 | | Corby | 5:05.80 |
| 2 | 33 | Isla WIDDOWSON | 16 | | Corby | 5:03.61 |
| 3 | 35 | Isabelle PAWLOWSKI | 13 | | Corby | 5:02.60 |
| 4 | 37 | Martha BLAKE | 13 | | Corby | 4:56.39 |
| 5 | 36 | Ava SINCLAIR | 14 | | Corby | 4:57.30 |
| 6 | 34 | Eleanor TRAHEARN | 16 | | Hinckley | 5:03.41 |
| 7 | 32 | Skylar GLENDENNING | 13 | | Corby | 5:05.74 |
| 8 | 30 | Sophie WRIGHT | 15 | | Hinckley | 5:06.09 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Cat | Club | Time |
| 1 | 39 | Faye EYTON-JONES | 15 | | Corby | 4:53.20 |
| 2 | 41 | Ella Mae PRIOR | 17 | | Corby | 4:40.81 |
| 3 | 43 | Phillippa CUTMORE | 13 | | Corby | 4:37.80 |
| 4 | 45 | Grace WINGHAM | 17 | | Corby | 4:30.00 |
| 5 | 44 | Beau CUNNINGHAM | 16 | | Corby | 4:30.10 |
| 6 | 42 | Holly COLEMAN | 14 | | Corby | 4:40.11 |
| 7 | 40 | Elisa GIRAUD | 13 | | Corby | 4:48.00 |
| 8 | 38 | Eva GALLAGHER | 16 | | Corby | 4:54.80 |