I search the Irish Family History Foundation's online database at ROOTSIRELAND.IE. It has abt 20 M church, civil, census, etc B/M/D and other records for MOST Irish counties. Only part of Co. Cork records have been transcribed into it.
For Margaret Sullivan B 1849 +/- 1 yr, Co. Cork, with a father forenamed Daniel, I found 2 records. However NEITHER have a mother's surname beginning with "D."
For Daniel Sullivan B 1845 ditto, I found 3 records. Ditto.
For Pat(rick) Sullivan B 1850 ditto, I found 4 records. Ditto.
If you are POSITIVE that the mother was surnamed D(riscol), then none of these are for your ancestor.
The Sullivan surname is highly concentrated in Cos. Cork and Kerry. Another (free) database IRISHGENEALOGY.IE contains some of the church records. I couldn't access this database at this time. Suggest you search it.