The Question and Answer section for The Open Window is a great resource to ask questions, find answers, and discuss the novel.
A faltering voice would give the impression of hesitance or possibly a lack of self confidence.
I don't know what you mean by "open Williams"?
Framton was not sure if she was married. Framton wonders to himself whether Mrs. Sappleton is married, and he notes signs of “masculine habitation” in the room