Hi, This is a long shot at best, but I have a DEVLIN, Mary (poss. Mary Catherine or Catherine Mary) and a DEVLIN, James born about the same time as your Devlins.Mine were in SC at some time or other and ended up in New Orleans, LA.
Mary married BUCKLEY, Thomas who was said to have been from Charleston, SC.Don't know if James was married.
This is just about the total of the information that I have except that James died btwn 27-30 yrs. of age.Mary died at about 47.