My great grandmother was Alice Devlin who married Hugh McCaffrey and lived at 1711 N. Fourth St. Phila.Alice's parents were Michael and Catherine Monahan Devlin. There were a number of Devlins living in the 1500 and 1600 blocks of Cadwalader St where they lived.I suspect that they were probably related.Michael apparently had a brother Frank who lived with them. Alice had sisters Catherine (Kate), and Ann and a brother Michael that I know of. Hugh and Alice and their family were active at St. Michael's. Does any of this connect with your Devlins?