Jim I have traced the marriage of Johanna Quillinan and Robert Fruin in Tipperay Parish on 28th February 1813 at the Family Search Mormon web site.
At the same site I have traced two births as follows 17th November 1833 Johanna daughter of Charles Quillinan and Anne Freuine in Tipperary Parish and also 26th November 1828 William son of Charles Quillinan and Anne Freuine in Tipperary Parish.
This Anne is too young to be Robert's daughter who was born on 8th May 1814 but she is more than likely related.
A Bob Frewin has given some background to his family line at http:\www.the-net.co.uk/frewin/messages/8.htm . As I mentioned before the Frewens were neighbours of the Quillinans in Carron and Barronstown and there appears to have been a number of marriages between these families.
I note from Bob's brief family outline that a Jeremiah Quillinan who was born c.1797 had a son Robert born c.1824.Both of these names(Robert and Jeremiah) also run through the family of Robert and Julia(Johanna) Quillinan.
There are many more entries for the Quillians on the Mormon site. I assume that you may have tried this source for information.If not, I can supply the information.