| B Final | |||||
| Lane | Comp.No. | Name | AaD | Club/Country | Time |
| 0 | 1 | Sophie Freeman | 14 | Plymouth Lea | 57.18 |
| 1 | 2 | Freya Colbert | 14 | Nova Cent'n | 56.43 |
| 2 | 3 | Betsy Wizard | 15 | Northampton | 56.17 |
| 3 | 4 | Jemima Hall | 17 | Wycombe Dist | 55.95 |
| 4 | 5 | Hanna Henderson | 16 | HPC-Ont CAN | 55.38 |
| 5 | 6 | Emily Peck | 17 | Hamilton UAE | 55.66 |
| 6 | 7 | Amy Grant | 19 | Loughboro Un | 56.16 |
| 7 | 8 | Athena Clayson | 17 | Mt Kelly | 56.38 |
| 8 | 9 | Elena Dewhurst | 15 | Anaconda | 57.17 |
| 9 | 10 | Jessica Shaw | 19 | Birm'ham Uni | 57.19 |