I couldn't find Killyfole or Crockarevan on Google maps so i'm obviously lost.
On the issue of proximity to Ballagh, if you search for Ballagh, Crockarevan, and Killyfole on the website link below (remember to specify County Fermanagh for Ballagh, as unlike the latter two, it's a fairly common name) and select 'map view' on the results, you will be able to see where they all are (you'll have to play around with the 'zoom' to read anything, but it's worth bearing with):
http://www.askaboutireland.ie/griffith-valuation/index.xml?action=placeSearchBTW, once you are in 'map view', there is a slide in the top right corner that lets you 'morph' between what you find on the old map and what is on a modern map.
I had no problem finding Crockarevan and Killyfole on the old map as they are right beside each other, however I initially struggled to see Ballagh - if you struggle likewise then I'd suggest, as an alternative, that if you find Crockarevan/Killyfole on the old map, pan to the
left / west approximately
4,800 metres as the crow flies (you can see the scale at the bottom, 200 metres is just under 2 centimetres), then you'll see it.
But just to help, if you keep to the right track on that 4,800 metre pan left / west, you will see a clump of three townlands - Corflugh above Coolnamarrow and Mountarby (Mount Darby) - then the townland of Tully (you have to pan up to see the name), then the townland of Tattycam (you are now in Galloon civil parish, having just left Clones civil parish), then the townland of Coolnasillagh (Coolnashillagh), before arriving at the townland of Ballagh.
So Ballagh is about 4,800 metres (only 3 miles, old money) from the nearest point of Crockarevan / Killyfole, which is why I posted the reference.