Bicycle (Bridge of Allan FK9)

My Ukrainian refugee friend is looking for a bike for her 12 year old son who is 5'6". The previous bike was unfortunately stolen. He would use it for getting to school.
Somewhere in Stirling or Cambusbarron or near either would be good. The boy would be driven to the collection point by his mum or me, and return home on the bike as it won't fit in his Mum's car or mine.