| Under-15 Girls 300 Metres HEAT 1 (Kingsmeadow Stadium, 14 May) | 1 | | Vivienne Jonczyk | (Hercules Wimbledon AC) | 43.44 | | | Q | | 2 | | Sophie Wright | (Herne Hill Harriers) | 43.90 | | | Q | | 3 | | Francesca Weal | (Guildford & Godalming AC) | 44.07 | | | q | | 4 | | Halili Waikwa | (Hercules Wimbledon AC) | 46.64 | | | | | 5 | | Anna Man | (Camberley & District AC) | 46.71 | | | | | 6 | | Katherine Lock | (Camberley & District AC) | 47.83 | | | | |
| | | Under-15 Girls 300 Metres HEAT 2 (Kingsmeadow Stadium, 14 May) | 1 | | Sophie Price | (Woking AC) | 44.15 | | | Q | | 2 | | Allegra Adams | (Hercules Wimbledon AC) | 44.98 | | | Q | | 3 | | Connie King | (Kingston AC & Polytechnic Harriers) | 45.72 | | | | | 4 | | Julia McDonnell | (Hercules Wimbledon AC) | 48.55 | | | | | 5 | | Nicole Wright | (Camberley & District AC) | 49.21 | | | | |
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