| 1) | Peabody, Clare | Brown | 4:25.55 (04/21-04/22) | 4:25.55 (04/21-04/22) | 4:26.46 (03/24-03/25) | 4:26.46 (03/24-03/25) | 4:27.17 (05/11) | 4:27.17 (05/11) | 4:28.76 (05/12-05/13) | 4:28.76 (05/12-05/13) |
| 2) | Hawthorn, Natalia | British Columbia | 4:25.55 (05/12-05/13) | 4:26.34 (05/25-05/27) | 4:31.95 (03/25) |