Looking for Flanagans (however it might be spelled!)

My maternal great great grandmother Maria Flanaghan arrived in Sydney, Australia in Dec 1870 on the Sabraon as an assisted migrant. The Sobraon was apparently the best passenger vessel sailing at the time and only carried first and second class passengers, implying that either Maria's family had some resources, or more likely her sponsor did. Maria travelled alone and according to the ship's register, had no relatives in Australia.  She was listed as a 20 year old Roman Catholic laundress who could both read and write. Her parents, both supposedly deceased were named as William and Margaret (I think).  Maria, working as a servant, married Charles Robert Thompson (an American mail driver) in Glen Innes less than 3 months later and had a child by him in early 1872 before he disppeared and life became very difficult - and tragic.  All this is detailed in my McCoy Doull tree on Ancestry. https://www.ancestry.com.au/family-tree/person/tree/36146526/person/28125155658/facts

I'd love to find out more about her family in Ireland.  The Griffith's evaluation in 1858 lists a William Flanagan in Bridge St. Boyle, a tenant of a house, office, yard and small garden owned by Viscount Lorton. There is also a Sarah Flanagan next door. The only death I can find for a William is in 1872. If this is the right William, then Maria was telling fibs when she arrived in Australia - but given her propensity for being liberal with the truth in subsequent years, perhaps this was just the first in a series of white lies. Knowing moer about her family might help explain some of the decisions she made later in life.  

Thanks, Jo