re: Maria Louisa Fitzgerald b.1803 chr. St Mary's Cathedral, Limerick, Ireland, dau ofJohn Fitzgerald and Ann Fitzgerald who married in 1797 in Limerick.
The only later record about that time of the Fitzgerald family that I have at home is one for Fitz-Gerald, "The Knight of Glin" of Glin Castle, co. Limerick. From Burkes "The Landed Gentry of Great Britain & Ireland" vol. 2, 1898. Starting with Thomas Fitz-Gerald, Knight of Glin, m. Mary, (dau. of John Bateman, of Oak Park, co. Kerry). Thomas will dated 17 Sep 1781, proved 18 Feb 1801. (so not parent of your Maria b.1803)
1. John, his heir, (mc.1789 ?) Margaretta Maria, ...(dau of John Fraunceis Gwynn, of Ford Abbey, Devon), ...and was s. by his only son, ...(does not mention any daus of John & Maria (?), ....but did they have daus ? ).
...1a. John Franceis Fitz-Gerald, Knight of Glin, ........M.A., J.P. and D.L., ........High Sheriff co. Limerick 1830, ........b. 28 June, 1791; ........m. 28 July 1812, Bridgetta, ........5th dau. of Rev. Joseph Eyre, of Westerham, Kent.
2.Elizabeth, m. Thomas Plummer, of Mount Plummer, co. Cork.
3. Frances, m. Rev. Thomas Lloyd, ...of Castle Lloyd, co. Tipperary.