Doherty won the first year girls race in impressive fashion to take the first gold of an action-packed day.
Doherty held off Clare McBride from Loreto, Milford and Laoise McGinley of Colaiste na Carraige to take the gold.
With Ellie Hegarty finishing in fourth, St Cecelia’s left with the first year girls team silver.
A record entry of 520 students from 26 schools across Ulster announced the return of secondary schools cross-country action at Finn Valley AC.
Schools from Donegal, Derry, Tyrone, Fermanagh, Monaghan and Antrim descended on the Millbrae as the event made its post-Covid return.
“It has been a very positive week,” said Finn Valley AC’s schools lead and Athletics Ireland Regional Development Officer Dermot McGranaghan.
“It’s great to see the kids back. We had 1000 kids here over three days. We have had huge positive engagement from teachers and schools.
“It has been brilliant and it’s great to see things coming back to normal.
“The big winners here are the kids.”