| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Backstroke | 1:12.30 | June Performance Meet 2025 | 2025-06-06 |
| 100m Backstroke | 1:08.14 | 2025 Kemp-Fry Invitational Swim Meet | 2025-11-28 |
| 100m Butterfly | 1:10.46 | June Performance Meet 2025 | 2025-06-06 |
| 100m Freestyle | 1:01.30 | June Performance Meet 2025 | 2025-06-06 |
| 100m Freestyle | 58.91 | 2026 AUS Swimming Championships | 2026-02-13 |
| 200m Backstroke | 2:35.65 | June Performance Meet 2025 | 2025-06-06 |
| 200m Freestyle | 2:14.40 | June Performance Meet 2025 | 2025-06-06 |
| 50m Backstroke | 32.81 | June Performance Meet 2025 | 2025-06-06 |
| 50m Backstroke | 31.08 | Amby Legere Invitational | 2026-01-24 |
| 50m Breaststroke | 38.37 | Amby Legere Invitational | 2026-01-24 |
| 50m Butterfly | 30.14 | June Performance Meet 2025 | 2025-06-06 |
| 50m Butterfly | 29.58 | Amby Legere Invitational | 2026-01-24 |
| 50m Freestyle | 27.96 | June Performance Meet 2025 | 2025-06-06 |
| 50m Freestyle | 27.53 | 2026 AUS Swimming Championships | 2026-02-13 |
Margaret Shackell's top personal bests include 100m Backstroke (1:12.30), 100m Backstroke (1:08.14), 100m Butterfly (1:10.46), 100m Freestyle (1:01.30), 100m Freestyle (58.91).
Margaret Shackell swims for University of New Brunswick.
Margaret Shackell has competed in 5 meets.