| Heat Number - 1 | |||||
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Chloe Richardson | 11 | Northampton | 3:55.10 |
| 2 | 3 | Annabelle Lucas | 11 | Northampton | 3:33.40 |
| 3 | 5 | Olivia Fern | 12 | Northampton | 3:13.90 |
| 4 | 7 | Milly Webb | 12 | Northampton | 3:02.80 |
| 5 | 6 | Sophie Rees | 11 | Northampton | 3:09.10 |
| 6 | 4 | Sophie Quennell | 12 | Northampton | 3:21.10 |
| 7 | 2 | Savannah Koriya | 11 | Northampton | 3:37.70 |