The baptismal records for Clones RC parish do not start until 1844. Marriage records started earlier.
The subscription site Rootsireland has a February 10 1835 marriage record in Clones for an Anne Maguire and a Thomas Maginnis. Thomas was from Cootehill Co. Cavan and Anne from Clones. Rose Byrne and Alice Cahill were the witnesses.
Likely Maria was born soon after the marriage.