EVENT 101 Female 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 1 | Kaylyn PRIOR | 12 | Corby | 7:12.20 |
| 4 | 3 | Evie BOURNE | 12 | Melton M'bry | 6:38.60 |
| 5 | 2 | Lucy DONNELLY | 12 | Corby | 6:58.28 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 5 | Seren STAPLEY | 13 | March | 6:32.50 |
| 2 | 7 | Arabella TYSTERMAN | 11 | Wisbech | 6:18.45 |
| 3 | 9 | Maisie BISHOP | 12 | Wisbech | 6:04.20 |
| 4 | 11 | Nyah SCOTT | 13 | March | 5:57.20 |
| 5 | 10 | Kaeley NAUGHTON | 15 | Kettering | 6:00.00 |
| 6 | 8 | Holly SMITH | 13 | Wisbech | 6:17.80 |
| 7 | 6 | Millie DAVIES | 12 | Corby | 6:31.00 |
| 8 | 4 | Cora THOW | 14 | Corby | 6:34.10 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 13 | Hannah BEEBY | 16 | Kettering | 5:40.50 |
| 2 | 15 | Codie LOWE | 14 | Corby | 5:39.33 |
| 3 | 17 | Riley WEBER | 12 | Corby | 5:30.40 |
| 4 | 19 | Saxon SWANN | 14 | Corby | 5:29.40 |
| 5 | 18 | Milana MISUROVA | 16 | Rushden | 5:29.89 |
| 6 | 16 | Esmee BROWNE | 14 | Rushden | 5:33.88 |
| 7 | 14 | Emma AFFLECK | 14 | Kettering | 5:39.80 |
| 8 | 12 | Julia RADAC | 15 | Rushden | 5:41.66 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 21 | Abigail TOMLINSON | 12 | Corby | 5:28.80 |
| 2 | 23 | Nika BUHHAROVA | 15 | Corby | 5:22.40 |
| 3 | 25 | Ivy BROWN | 13 | Melton M'bry | 5:19.60 |
| 4 | 27 | Isabella BURTON | 16 | Wisbech | 5:15.80 |
| 5 | 26 | Kitty PAYNE | 14 | March | 5:17.80 |
| 6 | 24 | Isabelle PAWLOWSKI | 13 | Corby | 5:20.10 |
| 7 | 22 | Georgia PARKER | 14 | Corby | 5:26.85 |
| 8 | 20 | Edith KABERRY | 14 | Corby | 5:28.80 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 29 | Marcie BLACKFORD | 15 | Corby | 5:10.39 |
| 2 | 31 | Faye EYTON-JONES | 16 | Corby | 5:00.90 |
| 3 | 33 | Melande BADENHORST | 14 | Corby | 4:48.50 |
| 4 | 35 | Lilly TAPPERN | 18 | Corby | 4:39.61 |
| 5 | 34 | Ella Mae PRIOR | 17 | Corby | 4:45.80 |
| 6 | 32 | Eva GALLAGHER | 16 | Corby | 5:00.00 |
| 7 | 30 | Ava SINCLAIR | 15 | Corby | 5:04.90 |
| 8 | 28 | Skylar GLENDENNING | 13 | Corby | 5:12.20 |