They are friends of Murphy & Catherine. They work & own the diner that Marge worked at. When Catherine was assumed dead a few years ago, it was actually Marge that had been killed, & Murphy found Catherine & assumed she was Marge, so he took her to the diner. She had no memories, so she thought she was Marge & became close to them & of course fell in love with Murphy. They come to visit them every now and then.