Who is Mrs. Canty from The Prince and the Pauper and what is their importance?

Mrs. Canty is Tom's mother. She is described as a warm, gentle, simple, quiet, and humble woman, who is unable to prevent her abusive husband from beating their son. She smuggles Tom food at night.... food she's saved from her own small portion. When Tom is mistaken for the Prince of Wales, his mother recognizes him during a procession. He pretends no to know her.... something that bothers Tom greatly.