Dicey’s Song isn’t all boats and aprons and piano lessons; there’s a dying, mentally ill mother hovering in the background the whole time. Although we never find out the specific mental illness from which Dicey’s mom suffers, it seems to be something like catatonic depression. In other words, she’s so depressed she can’t move, and spends her days lying in bed staring at the wall. When she dies, it’s one of the saddest moments in YA lit, but luckily Dicey has Gram, her siblings, and a new life in a new state to keep her from falling apart.
The book connects Momma's mental illness with their poverty, which isn't quite fair. It's clear from the beginning that she's sick, which has nothing to do with how much money she's got in the bank.
The real fear Dicey experiences in the novel is that she, or her siblings, will end up just like their mother.