Why does Edi come to feel guilty about being in the hospice center in the novel, We All Want Impossible Things?

After Ash, Edi, and Jude learn that the doctors can no longer treat Edi, they decide to have her admitted to a hospice in Massachusetts so as to protect Dash. Edi thinks this is the best thing for her son. However, a few weeks into her time at Shapely, she starts to regret her decision. She feels guilty for not being able to be there for her son.