Michael Coonan's second marriage

In 1856, the year following the death of his first wife Margaret, Michael Coonan decided to marry again. His second wife was much younger than him...Lucy Nihill had arrived in Melbourne from Ireland per the ship 'Stamboul' in August of 1854, aged 17 years.On the same ship was her mother, Mary, aged 38, and siblings Timothy, aged 15, and Eliza, 13.
The marriage certificate of Lucy and Michael stated that Lucy was the daughter of William Nihill, farmer, and Mary Coffe.It was noted that Michael Coonan was a widower, and that he had three children living and four deceased.
It also provided the information that Michael was a farmer residing at Brighton.
I have references to the Coonan holdings being selected in the areas of Epping/ Darebin Creek/Whittlesea and/or Wollert,presumably after his marriage to Lucy.These locations are all within a general area of 25km from each other, so I don't know if the references are to one property or several...hopefully a descendant of the Coonans will find this blog and put me straight!
It appears that there were no children born of this second marriage- none appear in the Victorian birth index or on the death certificate of Michael Coonan. In fact, the only reference that I can find to Lucy Nihill Coonan after her marriage was in a Victorian Government Gazette of 1861...
" CAUTION. My wife ,Lucy Coonan, having absconded from my residence and absented herself without my knowledge or consent, and without any just reason or cause, I hereby caution all parties against harboring her or giving her credit, as I will not pay any debts on her account.
Michael Coonan, Darebin Creek, 8th April, 1861."
The identical notice also appeared in the Argus of April 9, 1861.

I have searched for Lucy in the Victorian and NSW BDMs to no avail,under both 'Lucy Coonan' and 'Lucy Nihill'. She just seems to have disappeared off the face of the earth.
In 1860, the year before Lucy left her husband, there was a notice in the Argus about a court case between 'Nihill vrs Coonan'. No names were mentioned, but the plaintiff was referred to as 'she'.