You may be interested to look at the tree my sister and I have on our Webb family and others.
Your 3x Gr. grandmother Louisa Cubis is the great grandchild of William Cubis and Frances Fanny Webb. Frances Fanny was the sister of our ancestor John Webb.
Interestingly two of John Webb's granddaughters,another Fanny and Sarah,some years later died along with their husbands' and childen,when the the ship the 'Catariqui' sunk off King's Island Tasmania. They were just a day or so from their destination.
Here is the link to our tree-it will take you right to Mary Cubis.
Hope this if of interest