Character Analysis
Liza is the children's mother. She's had a rough go of it lately, so she decides to pack the kids up and head off to see her rich Aunt Cilla. In the middle of the night. Dicey has suspected for a while that things weren't quite right with Momma:
Lately she'd go to the store for bread and come back with a can of tuna and just put her hands over her face, sitting at the table. Sometimes she'd be gone for a couple of hours and then she wouldn't say where she had been, with her face blank as if she couldn't say. As if she didn't know. Momma didn't talk to them anymore, not even to scold, or sing, or make up games the way she used to. Except Sammy. She talked to Sammy, but even then they sounded like two six-year-olds talking, not one six-year-old and his mother. (1.1.18)
Turns out Momma was on the edge of a total mental breakdown. After Liza leaves the kids in the parking lot in Peewauket, she wanders off until she winds up in a mental hospital in Massachusetts. The doctors believe that she's in a cationic state since she won't respond to anyone or anything. Whoa—that's heavy.
But even though their mother has abandoned them in some of the worse circumstances, the Tillerman kids refuse to condemn her. In fact, they're comforted by memories of her. They sing the songs that she taught them; they like visiting the home she grew up in; and they long to be back home with her in the their house in Provincetown, which, aside from living with a mother who's mental health was slowly declining, was a very happy place to be.
In fact, when Dicey sees what it's like to raise a bunch of little kids on a shoestring budget, she actually pities Momma:
Was this how Momma felt? Was this why Momma ran away? Because she couldn't think of anything more to do and couldn't stand anymore to try to take care of her children. (1.6.126)
Maybeth and Sammy also have a really strong connection to her. Sammy, for his part, is sure that Momma is going to come for them someday. Keep dreaming, little guy. Only James has any kind of animosity toward her—he says that he doesn't blame their father for leaving because Momma "could drive you crazy" (1.3.131). Oh, but you know how James is. He's so black and white about everything.
In the end, Dicey refuses to write Momma off completely. When Cousin Eunice announces that she'll take in the Tillermans and be a "good mother" to them, Dicey tells herself that they "already have a good mother" (1.11.179). We might dispute that, but Dicey never does. She affirms the same thing to their grandmother:
"She went off and left you," their grandmother said.
"She wanted to come back," Sammy said.
"How do you know that," their grandmother said. She didn't ask it, she said it.
"Because she loved me. Didn't she, Dicey?"
"Yes, she did. She loved all of us," Dicey said.
"Humph," their grandmother said, reaching for another crab.
The Tillermans had won that battle. Dicey knew it. She knew it as close to her bones as she knew that Momma did always love them. (2.8.236-242)
Dicey never has any doubt that their mother cares for them. She didn't leave them because of something they did or some failing on her part—it was mental illness that tore their family apart. And that's nobody's fault.
Liza's Timeline