One of volunteers, Shane Wilson, assisted me with your query. The two civil marriage records are below (which you may already have) and it appears the parties all lived in St. Thomas parish. The marriages were held in the Registry office which according to Shane could mean a mixed marriage or a marriage without family approval or they just wanted to get married quickly.
Civil registration of deaths did not begin until 1864 and we could not locate any church death records. Also did not find a baptismal record for Charlotte.
Shane also found some potential info on the elder James Flavelle on the subscription site FindMyPast.
there is a James Flavel in the RIC records (FMP) service no. 170, born Co. Armagh, served 1824 to 1849 in counties Fermanagh & Cavan