Hello Lauren,
Edmund Bathurst Cotter married two sisters, Dorothy Eileen Moulds and Daisy Evelyn Moulds. They were the daughters of Walter James and Ethel Emily M. Moulds (nee Hunt). Edmund married Dorothy in 1931 in Parkes, and he married Daisy sometime after 1966 I believe, but I don't have the details (Dorothy died 22 February 1966 in Parkes).
I have some details of Edmund and Dorothy's descendants (they had seven children), but as there are many still living I won't post those details here. If you write to me at dafydd at iinet net au I'll send what I have to you.