| Event | Time | Meet | Date |
|---|---|---|---|
| 100m Backstroke | 1:21.43 | 2025 Prairie Winter International | 2025-12-11 |
| 100m Breaststroke | 1:43.38 | Norm Banfield Memorial Open Development Meet | 2025-10-03 |
| 100m IM | 1:30.47 | Norm Banfield Memorial Open Development Meet | 2025-10-03 |
| 1500m Freestyle | 5:45.77 | Spooktacular Goldfins Invitational 49 | 2025-10-24 |
| 200m Backstroke | 2:52.19 | Spooktacular Goldfins Invitational 49 | 2025-10-24 |
| 200m Breaststroke | 3:29.88 | Norm Banfield Memorial Open Development Meet | 2025-10-03 |
| 200m Freestyle | 2:56.30 | Norm Banfield Memorial Open Development Meet | 2025-10-03 |
| 200m IM | 3:00.58 | 2025 Prairie Winter International | 2025-12-11 |
| 400m Freestyle | 5:53.30 | 2025 Prairie Winter International | 2025-12-11 |
| 50m Backstroke | 38.39 | Spooktacular Goldfins Invitational 49 | 2025-10-24 |
| 50m Breaststroke | 47.51 | Norm Banfield Memorial Open Development Meet | 2025-10-03 |
| 50m Butterfly | 36.92 | 2025 Prairie Winter International | 2025-12-11 |
| 50m Freestyle | 35.42 | Norm Banfield Memorial Open Development Meet | 2025-10-03 |
Grayston, Gillian's top personal bests include 100m Backstroke (1:21.43), 100m Breaststroke (1:43.38), 100m IM (1:30.47), 1500m Freestyle (5:45.77), 200m Backstroke (2:52.19).
Grayston, Gillian swims for Team Gold.
Grayston, Gillian has competed in 7 meets.