Many thanks for your post to the Ireland Reaching Out message board. Would you have any more information about the Keoghs who emigrated in 1848? What were their ages?
In looking on the Roots Ireland database, I see a John Keogh baptised 20 June 1841 to a James Keogh and a Mary Moore. The parish is Blanchardstown in County Dublin. I do not see any reference to other children's baptisms for this couple, but you might find them if you look at the Blanchardstown parish registers on the National Library of Ireland website at this link: https://registers.nli.ie/parishes/0466
For ease of reference, here is the link to the page with John Keogh's baptism record which shows that the sponsors were: Patrick Keogh and Anne Moore.
https://registers.nli.ie/registers/vtls000633357#page/116/mode/1up The entry is at the left hand side of the page about mid-way down. You will see that the address was noted as the "Low Road".
If you have any further information, please add it to this post.
All the best,