Thanks for your enquiry.The Bertha Schubert you mention is not in my Schubert family tree.
My original Schubert ancestor in Australia, Robert Schubert (1838-1920), came to Victoria in the mid 19th century and later moved to NSW and I have full details on all his descendants. However there was a large family of Schuberts who settled in South Australia in the 19th century and a book has been published about them. I bought a copy but cannot find it at present.
May I suggest that you do a Google search for a book with the name Schubert in the title. The book is very comprehensive and details the descendants of some Schuberts who, as I recall, were leaders in the development of the S.A. wine industry. I'll have another look for my copy of that book and if I find it, I'll let you know.