When someone you love takes their own life, guilt is unavoidable; when they hold you responsible, guilt is off the scale. The sister of Canadian novelist Martha Baillie, Christina, killed herself at 61. On the wall, in blue marker, she’d written three reasons for wanting to die: “Because of schizophrenia / Because of The Juniper Tree / Because of losing the house”. The schizophrenia went a long way back; she’d first attempted suicide in her 20s. By “The Juniper Tree” she meant a Brothers Grimm fairytale in which a child is killed by one parent and fed in a stew...