In the 3rd class party scene.
The 3rd Class Irish Woman was a third class passenger on the RMS Titanic. She was the wife of the Third Class Irish Man, who played the music in the third class party scene. She eventually died in the freezing waters.
She was played by Linda Kerns. She is not to be confused with the Third Class Woman with a baby, as she had a French accent and was played by a different actress.
Biography 
Edit
Her corpse, as seen in the water.
She is first shown with her husband at the ship's top deck, in the scene where the passengers are waving goodbye at Southport. The couple were right behind Jack and Fabrizio.
She is then seen in the third class party scenes here and there. She is the woman who exclaims, "Jesus, Mary and Joseph!" as a reaction to Rose's toe-standing skill. Later on in the film, as the ship is tilting, she can briefly be seen with her husband and other passengers on the deck holding onto Thomas Byles as he quotes the Book of Revelations.
Her last appearance was her deceased body in the icy waters. Her body was shown right after one of the officers say "check them", where one replies "these are dead, sir".
Deleted scenes Edit
In the first deleted scene, she is briefly seen in the background jiving to a man playing the piano.
In the second (and last) deleted scene, she gives Rose a coat, saying, "here ma'm, cover yourself". Rose thanks her. Her husband offers Rose and Jack a flask of brandy as it will "take the chill away", where Jack drinks it and replies "cheers".
