| B Final | |||||
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 1 | Rachel Bethel | 18 | Bangor IRL | 4:17.70 |
| 1 | 2 | Nicole Ryan | 20 | Co Oxford | 4:16.61 |
| 2 | 3 | Maisie Elliott | 15 | Co Leicester | 4:16.12 |
| 3 | 4 | Caitlin Mackay | 17 | Wycombe Dist | 4:15.85 |
| 4 | 5 | Jemima Hall | 17 | Wycombe Dist | 4:15.62 |
| 5 | 6 | Mollie Wright | 20 | Nova Cent'n | 4:15.83 |
| 6 | 7 | Betsy Wizard | 15 | Northampton | 4:16.09 |
| 7 | 8 | Mia Slevin | 15 | Derventio | 4:16.53 |
| 8 | 9 | Meghan Byrne | 18 | Barnet Copt | 4:17.06 |