The 14-year-old athlete, from Eckington, is a pupil at Eckington School. She competes in the 800m and won gold medals and set new championship records at the England Athletics U15 / U17 / U20 Indoor Championships, the English Schools Championships, and the England Athletics U15 / U17 and IPC Championships.
Tilly says: "I joined Hallamshire Harriers Athletics Club in 2012 after winning a schools cross country race. Since then I have become the junior girls English schools 800m champion in a new championship-best time of 2.06.22, breaking the Under-15 girls all-time British record and the English schools record which had stood for 28 years.
"I have also become the National outdoor and indoor 800m champion, again in record breaking times, and I have also been selected to represent England twice in the Schools International cross country in both 2014 and 2015.
"Currently, I train five times a week and three of these sessions are with Hallamshire Harriers.
"On a Monday I work on my speed and core with my athletics club at either the English Institute of Sport or Woodbourn Road Athletics Stadium.
"Tuesday and Thursday are the days when I do my main sets on the track and the amount of distance we do increases towards the cross country season in order to help improve my stamina and endurance.
"I also train Wednesday and at the weekend, which involves core training and distance runs.
This season my goal is to be selected for the Great Britain team at the first European Youth Athletics championships held in Tbilisi, Georgia in 2016 for the 800m (under-18).
"I am also aiming to have a better cross country season this year and again aiming to be selected for the England team in the SIAB XC for a third year running, which will be held in Scotland.
"My long term goal is to become a professional athlete and represent my country at the world stage. Running consistent times is something I will always aim to achieve."