If the Forbes family arriving on the Theodore is yours you might be interested in the William who is also listed.
William Forbes Farmer Riddells Creek 28 Sep 1864 37/605 VPRS 28/P0, unit 461;digitised will,Vic.
has a wife Eliza a daughter Janet and a son Donald. (note two Donalds,on the Theodore) . Might not be yours of course. This Donald also is involved with horses, and working on a station in NSW.
Index of some Alexander deaths Vic
FORBES Alexander F James m JORDAN - Mary 1869 3960
FORBES Alexander F James m MUNCKTON Mary 1875 15181
FORBES Alexander Simpson F Alexander m COSTELLO - Jane Mary 1879 653
FORBES Alexander F John m FRASER Martha 1873 4118
cheers penne