EVENT 102 Female 09/Over 100m Butterfly - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 1 | Helena HAMILTON | 12 | Grantham | 1:59.03 |
| 2 | 4 | Paris CABORN | 11 | Louth | 1:49.00 |
| 3 | 6 | Amy FOSTER | 10 | Louth | 1:46.24 |
| 4 | 8 | Juliette KING | 12 | Grantham | 1:45.00 |
| 5 | 7 | Eden DYSON | 12 | Grantham | 1:45.00 |
| 6 | 5 | Amelie MORRIS | 12 | Boston | 1:47.65 |
| 7 | 3 | Hollie-Anne CROOK | 10 | Grantham | 1:50.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 10 | Abbie MACKIE | 14 | March | 1:43.63 |
| 2 | 12 | Isabelle CLAYTON | 11 | Grantham | 1:41.60 |
| 3 | 14 | Elisabeth KINNEAR | 14 | Grantham | 1:40.00 |
| 4 | 16 | Niamh O'DONOGHUE | 12 | March | 1:35.19 |
| 5 | 15 | Daisy-Grace WILDISH | 9 | Retford | 1:38.60 |
| 6 | 13 | Isla-Rose WILDISH | 10 | Retford | 1:41.04 |
| 7 | 11 | Mia PARAPIJONAVICIUTE | 15 | Grantham | 1:41.62 |
| 8 | 9 | Ava-Grace GREGORY | 12 | Grantham | 1:44.70 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 19 | Maya GLASSFORD | 13 | Melton M'bry | 1:31.55 |
| 2 | 22 | Lizzy LERESCHE HANDS | 12 | Grantham | 1:24.42 |
| 3 | 24 | Lucy WILLATTS | 12 | Grantham | 1:23.72 |
| 4 | 26 | Erin NORTON | 13 | Boston | 1:20.81 |
| 5 | 25 | Grace HOWITT | 15 | Grantham | 1:21.16 |
| 6 | 23 | Vilte ROPEIKAITE | 15 | Boston | 1:24.20 |
| 7 | 20 | Annie WEBSTER | 12 | Grantham | 1:26.91 |
| 8 | 17 | Charlotte GOSLING | 14 | Newark | 1:34.71 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 28 | Milen MERRITT | 12 | Melton M'bry | 1:19.77 |
| 2 | 30 | Amelia BIRD | 13 | Skegness | 1:18.65 |
| 3 | 32 | Harriet MCCORMACK | 14 | Grantham | 1:14.70 |
| 4 | 34 | Grace TURNER | 16 | Grantham | 1:07.26 |
| 5 | 33 | Ellena HOWITT | 13 | Grantham | 1:13.50 |
| 6 | 31 | Megan RUTT | 14 | Boston | 1:18.12 |
| 7 | 29 | Amy TAYLOR | 13 | Grantham | 1:18.98 |
| 8 | 27 | Emilija IVANOVA | 15 | Boston | 1:20.16 |