I checked the Roots Ireland indexes and I located 4 of the 7 baptismal records and as you indicated the marriage record is not on Roots either.
Roots does not have all the South Tipperary parishes online so since the marriage would have occurred in the bride's parish maybe the records for that parish are not online and may not exist pre-1830.
The same issue may be a reason for not finding the other baptismal records or possibly the Cahir records have some gaps which is common back to that time period.
Later this summer the National Library of Ireland plans to put the RC parish registers online for free searching. I would look at the Cahir records and maybe parishes close to Cahir to see if you can locate the missing records.