Catherine is my GGG Grandmother. In 1863 her parents Mary and George Brown submitted an application to have Charlotte (5), Catherine (3) and Harriet (not quite 2) admitted to Queen's Orphan School. Whilst the two older girls were admitted Harriet was not.
It was discovered that George was not the biological father of Harriet. Mary (under the alias Bridget Breen) lived with a man Patrick Mulligan during Georges incarceration. Patrick is the biological father of Harriet. He is also the father of another child to Mary - Mary Mulligan born in 1863.
A newspaper article describes a court hearing BREEN vs MULLIGAN. This article uncovers yet another alias for Mary (Margaret Breen). This court case identifies that Patrick took custody of Mary Mulligan.
Reference can be found of an application by Mary Brown and Patrick Mulligan to have Harriet admitted to Queen's Orphan School (SWD26/1/7 Image 129 (2 pages)
I have been undertaken extensive research on both Mary (Bridget O'Brien) and George Brown. This has uncovered a very large number of alises used by both.