EVENT 338 Girls 15 Yrs/Over 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 3 | 2 | Charlotte Lamb | 15 | Etwall | 5:28.50 |
| 4 | 4 | Jessica Wass | 15 | Co Derby | 5:27.40 |
| 5 | 3 | Sophia Lewis | 16 | Co Derby | 5:28.30 |
| 6 | 1 | Ellie Rayner | 15 | Rykneld | 5:29.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 6 | Saffron Sands | 15 | Ripley | 5:23.00 |
| 1 | 8 | Chloe Montgomery-White | 15 | Buxton | 5:22.10 |
| 2 | 10 | Eleanor Torpey | 19 | Ashbourne | 5:15.50 |
| 3 | 12 | Jessica Parry | 15 | Long Eaton | 5:13.10 |
| 4 | 14 | Mia Wilson | 15 | Long Eaton | 5:08.90 |
| 5 | 13 | Freya Lester | 16 | Matlock | 5:11.30 |
| 6 | 11 | Rosie Stone | 16 | Ripley | 5:14.30 |
| 7 | 9 | Millie Cadden | 16 | Co Derby | 5:20.20 |
| 8 | 7 | Connie Rennard | 15 | Repton | 5:22.40 |
| 9 | 5 | Darcie Willis | 16 | Eckington | 5:23.30 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 16 | Emilie Kummerfeld | 18 | BelperMarlin | 4:57.30 |
| 1 | 18 | Sophie Millidge | 17 | Swadlincote | 4:54.30 |
| 2 | 20 | Matilda Hase | 16 | Long Eaton | 4:53.70 |
| 3 | 22 | Samanta Millere | 16 | Repton | 4:49.00 |
| 4 | 24 | Sophie Martin | 16 | Chesterfield | 4:46.30 |
| 5 | 23 | Anna Tyers | 15 | Co Derby | 4:46.60 |
| 6 | 21 | Millie King | 15 | Co Derby | 4:51.93 |
| 7 | 19 | Abbie Tunnicliffe | 15 | Long Eaton | 4:53.90 |
| 8 | 17 | Alice Marriott | 17 | Repton | 4:57.30 |
| 9 | 15 | Isabelle Brailsford | 16 | BelperMarlin | 5:02.55 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 0 | 26 | Poppy Mathias | 17 | Repton | 4:43.53 |
| 1 | 28 | Eleanor Broughton | 17 | Repton | 4:32.20 |
| 2 | 30 | Hannah Hodgkiss | 17 | Repton | 4:30.30 |
| 3 | 32 | Holly Marshall | 17 | Repton | 4:28.40 |
| 4 | 34 | Henrietta D'Ammassa | 18 | Repton | 4:23.38 |
| 5 | 33 | Harriet Oxley | 18 | Repton | 4:26.40 |
| 6 | 31 | Sophie Busby | 17 | DerbyPhoenix | 4:30.20 |
| 7 | 29 | Eja Coe | 17 | Co Derby | 4:31.21 |
| 8 | 27 | Lucy Cadden | 19 | Co Derby | 4:38.90 |
| 9 | 25 | Poppy Mead | 18 | DerbyPhoenix | 4:43.70 |