Actually......

Carrie and Nick--2 children from London are sent to Wales to live with a volunteer family, to keep them safe from the bombing in London. They know where their mother is, but they can't live with her just yet.

Mr Evans and his sister--the family that volunteered to take them in. They do run a small shop like a grocery store, but Mr. Evans bigger job is as the minister of the local church (probably Anglican).

Hepzibah--I'm not sure if she calls herself a witch or others do. I think that she preferred to call herself a "wise woman", due to the fact that she is knowledgeable about herbs and herbal healing arts.

Joy