Chris and Sallyann:
Can you advise what information you have on Martin Ryan and his parents? I only see just the baptismal record for Martin in 1845 and no baptismal records for siblings. Did Martin Sr. and Mary and Martin Jr. emigrate post 1845?
Drumraney civil parish and the related RC parish of Drumraney are in the southwest corner of Co. Westmeath between Co. Longford to the north, Co. Roscommon to the west and Co. Offaly to the south.
The death record you found is not for your Mary Brown. She would have been shown as Mary Ryan on the death record and Mullingar is not the registration district for people who live in Drumraney civil parish.
There were no Ryans listed in the 1853 Griffiths Valuation head of household listing for Drumraney civil parish and no Ryans in the 1901 census for the parish. There were a number of Brown/Browne families in both files.
Let me know and we can see if we can assist further. Just so you know I live in the States.