If the records which Roger found turn out to be relevant, then you may be in luck. The parish records available online for Philipstown (also called Daingean) go back to 1820 for both baptisms and marriages. There is also an older period of coverage for baptisms, from 1795-1798, where I was lucky enough to find my own great-great-grandfather's baptism. You can search those records at this link: https://registers.nli.ie/parishes/0723
The parish of Edenderry is just to the east of Philipstown/Daingean. The parish records there also go back to 1820, and you can search them at this link: https://registers.nli.ie/parishes/0704
At each of those pages (both on the NLI site), you'll see an interactive map which lets you move on to other parishes in the area, in case neither of the above works out.
If you find relevant records, in most cases those registers list the townland within the parish in which the family lived (at least for baptisms, but often not for marriages). If you locate that townland, then you can look up more info about it at one of these pages (it should be listed at one of these pages):
Upper Philipstown: https://www.townlands.ie/offaly/upper-philipstown/
Lower Philipstown: https://www.townlands.ie/offaly/lower-philipstown/
Edenderry Urban: https://www.townlands.ie/offaly/edenderry-urban/
Edenderry Rural: https://www.townlands.ie/offaly/edenderry-rural/
