The first Flannery surname (any spelling) was found in the 1851 Baltimore City directory.  That listing was for

Occurrences of Flannerys were sporadic in the earliest years.  Generally, only the head of household and working age males were listed.  Females tend to show up most often when they are widowed or if they are running a business, i.e., grocery or confectionary, in addition to the husband's line of work.  Young working females were not common in the earlier years but begin to be listed in about the 1880s.

Also be advised that there tends to be a lag of at least a year in the directories.  In other words, a person may die in 1876 but still show up in the 1877 city directory.  Therefore it is recommended that several sources (census, baptism, marriage, burial, and/or obituary records) are used to get a real sense of where and when Flannerys were found in Baltimore.