This school has appeared on the map as part of the recent work on mapping buildings in Ireland.   However, I think it's not really there.  It shows as rubble on the recent Bing imagery, and only appears on the (older?) ESRI Clarity imagery.

Further, it does not appear as a currently-operating school on the gov. lists.   I think it has been amalgamated into Our Lady and St Patrick's to the north.  Search the DENI site for refs 403-1644, 403-1384 and 403-6693 to see what I mean - http://apps.education-ni.gov.uk/appinstitutes/

So - who has on-the-ground local knowledge and can confirm the existence or otherwise of this institution?