Hampered by early injuries when making the transition to under 15 level, Mollie came 4th in the Sandra Luke Memorial 5 Star Competition at Oxford at the end of May, winning both the 100m and 200m races, a feat she emulated three weeks later for Charnwood in the YDL fixture at Coventry. In between she won the silver medal in the Leicestershire County Schools Championships 200m. Representing Leicestershire in the Northern Counties meeting at Nuneaton she came 1st in her 100m race.

Still at under 13 level Mollie completed the 2015 100 metres indoor season ranked UK number 1. At the Birchfield Open she won gold medals in the 75m, 150m and long jump respectively, came 1st in the same three events at the opening YDL Midland Premier fixture and followed this with three more victories in the second fixture.
In June Mollie won a gold medal in the 100m at the Leicestershire County Schools Finals and anchored the 4 x 100m relay team to another gold medal. She won gold medals in the 100m, 200m and long jump at the Wenlock Olympics and won the 75m, 150m, long jump and was part of the victorious 4 x 100m relay team at both the third and fourth YDL Midland Premier matches. In September she was selected for Leicestershire in the under 15 Northern Counties meeting, winning the 200m, anchoring the 4x100m relay team to victory and coming 2nd in the long jump, followed this the next day with gold medals at the Derby Athletics Festival in both the 100m and 200m and retained her title as Charnwood's under 13 Champion athlete.

Moving up to under 13 in 2014 she won the Leicestershire Challenge, a quadathlon competition for year 5/6 girls, and finished her indoor season ranked UK number 8 at 100m with a time of 14.01 secs. In May Mollie won the Leicestershire Quadkids competition for year 5/6 girls by 10 points and followed this by becoming Leicestershire Under 13 Long Jump Champion at the Two Counties meeting in Nuneaton where she was also runner-up in both the 100m and the 200m. A week before her twelfth birthday Mollie was selected to represent Leicestershire & Rutland under 13s at both 100 & 200 metres in the Northern Counties meeting and in September she became Charnwood's under 13 Champion athlete in a competition comprising a run, a jump and a throw of her choice.

Mollie finished 2013, her first year in athletics, on a high, completing 100m in 14.2 seconds at her home club championships in September, to achieve a final UK ranking of number 2 at under 11 level to add to top ten rankings in three other sprint distances, and six days later won gold and silver in the 80m and 150m respectively at the Derby Athletics Festival