For future reference it would be worth enquiring whether they have a child accompaniment service.
Both our kids have flown alone in the past - not to/from Turkey, admittedly, but both outward and return journeys to Ireland, Northern Ireland and Hong Kong - and on each occasion the airline made sure there was a crew member available to assist with check-in and boarding, look after them properly on the flight, and ensure they got off, retrieved their baggage was and were delivered safely to whoever was meeting them. Didn't cost much either as I recall - in fact, there was no charge on the Northern Ireland flights, presumably because it was within the UK.