Lady Hatt is Sir Topham Hatt's wife and is a kind and gentile woman. The engines are extremely fond of her and like when she visits the railway or ride in one of their coaches. Although she usually praises the engines for their good deeds, Lady Hatt will also scold the engines when they act up or behave properly. Although we have never met Sir Topham Hatt's and Lady Hatt's children, we do meet their grandchildren during their vacation to the seaside.