you need to supply more info.
did your g-g-g/mother live in England ?
If so where ?
who did she marry, and where ?
what were her childrens names, where were they born ?
Was she Catholic or some other religion ?
The more info you have, the better your chances are of finding her.
There are no birth records in Ireland for early 1800s.
Earliest records in Ireland 1864 for Catholic Births, Deaths, Marriages.