A nurse was at the nursing station in St. Francis Hospital, Iowa when Kate went to visit her dying mother. ("Born to Run") The nurse directed Kate to her mother who was in room 208 telling her to go down the hall, around the corner and she will find her in the room on her right.
Although being an unnamed character, the nurse is in fact named, as her name is shown on her staff badge. However, her name is unidentifiable in the episode. Therefore, she is considered as an "unnamed character".