Carol, how are you again, so quick. I see an 1891 marriage of a Catherine Young to a Patrick Reilly in Dundalk, her father is an ex policeman at this stage and she also lives in Ladywell, are you aware of this free site, you sign in, civil records are there with all births back to 1864, first year of registration, and marriages back a certain date and deaths also and on to 1965, births to 1915 I think, https://www.irishgenealogy.ie/en/ the church records are not online for Dundalk or Louth, mainly Dublin and Cork / Kerry only. Church records are online here for RC but you need a year and month or frustration sets in, can be a tricky read, https://registers.nli.ie/
I searched all Young with a mother Barbara and found 6 births in Louth, Catherine 1869; Liz 1873; Edward 1866; Jas or Jock 1864; Barbara 1863 and Margaret 1861. The registration district is for Ardee for the four post 1864 and the family lived in Dunleer, I see another Young family living in Drumcar also, just unusual name in colse proximity.
Here is an interesting Louth site, http://www.jbhall.freeservers.com/ I see reference to the name young going back to the late 1700s there.
However Carol we really need to see the service record of the policeman to establish where he is from, his pension records should also be available with a bit of searching, most of the actual records are I think held in Kew in London but are available to find elsewhere I think. I will search an online site to see if I can locate ay mention of him or have a look for the book. I found no marriage to suit but as only church records are aavailable they may not exist or have being lost. The othere possibility is they married outside Ireland which takes me back to the service record for information, tehre ar 3 Edward marriages between 1849 and 1861, the one in Meath most suitable date wise is not correct as the wife is of a totally different name, there are a lot of Robert marriages and mostly in Tyrone or other northern counties, as in now Northern Ireland. The only Young with a wife Barbara is married in Tyrone but it was a James Young.
Regards
Pat