I believe we may be from your branch of the family. My grandfather was Thomas Lancelot Cubitt 1880 who was the son of William Robert Cubitt 1842 and Amelia Jane Carter formerly Box. His father was Martin Cubitt of Waxham and his mother was listed as Mrs Cubitt on family search and Martin's parents were Robert Cubitt and Rebecca Mann also of Waxham. I think it then went to Robert Cubitt 1745 and Martha Colk 1754. I only have this information off some patron sheets sent in to family search (LDS). They were compiled by G.E.S. Cubitt.
My mother was the eldest daughter of Thomas Lancelot Cubitt and Ruby Elma Balchin she married Ernest Edward Brealey. I don't know when he came to Australia, I am an only child. Thomas's youngest daughter was Nancy Jessy Dawn and she had 3 children.
I hope this information may be of interest to you. Jan Lindner