Beloved's "unlined hands"

While Beloved is living with Sethe and Denver in human form, Morrison constantly references to her "unlined hands". The first few times this came up, I underlined it not sure of what it meant. As I was finishing the book today it occurred to me, that the lines on the palms of our hands are also referred to as life lines.
On another note, did anyone else think it was strange that Denver and Sethe never made a big deal of the fact that Beloved was back from the dead ? She dies so tragically and they are haunted by the memories and her spirit for eighteen years, but when the human Beloved shows up this all sort of dissolves, at least on the surface. Sure, Denver longed for a companion and Sethe saw it as a second chance with Beloved, enabling her to forget her painful past, but wouldn't expect them to at least wonder why Beloved had rejoined them on earth ?