I am just going by his obit and funeral notice:
Sunday Times Perth, 1 August 1926 page 3.
MR. RICHARD DONOVAN
He was born at York, Western Australia on October 15, 1850, and was the youngest son of Mr. John Donovan, farmer, of York. The deceased was a member of the mounted police, and served at Perth, Mt. Barker and Geraldton, and was in charge of Mt. Wittenoom until he resigned in 1896. After his retirement he resided at Osborne Park. He leaves a widow, two sons, three daughters, thirty grandchildren, and one great-grandchild.
(Photo included with the obit)
His funeral notice says he is the beloved husband of Mary Ann. (see TROVE newspapers online)
Mary Ann's notice in 1942 names her children including Richard Herbert.
I obviously haven't seen any documentation such as BDM certificates but I can see that Richard DONOVAN and Mary ROACHE moved to Victoria and had further children there. It appears that they were publicans.
Your DONOVAN/ASHBY marriage certificate should name both their fathers.