So no one here had any obvious answers on this one. If you are still trying to identify them then I think there are a number of strategies you could consider. Firstly trying to find others researching the Coyle family.
If you know the actual parish in Cavan for this family you could join Ireland Reaching Out at https://irelandxo.com/
and then join that parish on Ireland Reaching Out and post the picture and query on their message board.
Have you a Facebook account or at least access to one via a family member? Facebook can be very handy for crowdsourcing your Irish genealogy. There is an active Cavan genealogy page http://www.facebook.com/groups/cavangenealogy and I suggest you post the photo and query there also.
Here is a Rootschat piece from someone researching Coyle family in Cavan http://www.rootschat.com/forum/index.php?topic=154445.0
If you have access to Ancestry.com search there to see if anyone has a tree there for this Coyle family and send them a message.
If none of the above work then you could also try posting on some of the Coyle family pages on Facebook – note the biggest one appears to be Coyle family Donegal rather than Cavan.
Do let us know how you fare.