Who is Roberta Jaskiewicz from She's Come Undone and what is their importance?

Roberta Jaskiewicz lives across from Dolores' grandmother. She runs a tattoo parlor. Dolores' grandmother seems to hate Roberta, though she does check on Roberta once during a snow storm. Roberta eventually becomes an important person in Dolores' life after Dolores moves back to her grandmother's house in Rhode Island.