For Pat(rick) Dolan B 1821 +/- 4 yrs, Co. Roscommon, I found 6 rcds: 1817 Castlerea, 1818 Elphin, 1821 Elphin, 1822 Elphin, 1825 Croghan and 1825 Elphin RC parishes. Father's respective forenames were Patrick, Michael, Nicholas, Laurence, John, and Patrick.
For Bri(dget) Dolan B 1830 ditto, I found 9 rcds: 1827 Aughrim, 1829 Castlerea, 1829 Elphin, 1830 Loughlynn, 1831 Roscommon, 1833 Castlerea, 1833 Aughrim, 1833 Aughrim, and 1834 Croghan RC parishes. Father's forenames were Patrick, James, Patrick, John, Patrick, Bernard, John, John, and Patrick.
For Marg(aret) Dolan B 1830 ditto, 4 rcds: 1827 Croghan, 1828 Roscommon, 1832 Roscommon, and 1833 Loughlynn RC parishes. Father's respective forenames were Michael, Patrick, Patrick, and James.
I don't see any common matches for the same parish and father's name in any of the above. You might try expanding the search range; ca 1830 +/- 4 yrs may not be broad enough.