I have some information on the arrival of you Mary Roberts (Robert). From the book 'Guernsey Immigrants to Australia' it says the following:
Roberts - Marshal Bennett (that's the ships name) - Geelong - 1854.
Mary, 25, general servant.
If you are on Facebook try joining Guernsey Family History. We have a few members of the Robert/Ingrouille family. https://www.facebook.com/groups/Guernseygenealogy/
I have a new tree on Tribalpages with this family. If you would like access to my tree send me your email address. My email is listed in a reply further up.