- For other uses of "Isabella", see Isabella (disambiguation).
A sick Isabella, some hours before her death. ("Ab Aeterno")
Little is known about her early life. She hoped to one day travel to the New World with Richard, and start a family. At some point, she was afflicted with tuberculosis. By 1867, this illness brought Isabella to her death bed, where Richard lovingly stayed by her side. She gave Richard words of assurance and bestowed her cross necklace upon him. Richard then rushed to the doctor to retrieve help, but by the time he returned, Isabella had already died. ("Ab Aeterno")
In the Black Rock
Richard tells Isabella to run. ("Ab Aeterno") (promotional still)
When Richard was confined within the Black Rock as the only survivor, the Man in Black visited Richard in the form of Isabella. The apparition told Richard that they were in "hell" and that she had narrowly escaped "The Devil". Isabella told Richard that she intended to save him and attempted to unchain him in vain. Upon hearing the warning howl of the Smoke Monster Richard begged Isabella to run, but she refused to leave him. Once Richard's pleas became desperate the apparition fled above deck, whereupon Richard heard sounds of the Smoke Monster's attack. ("Ab Aeterno")
2007 (Communication With Hurley)
Richard feeling Isabella's presence. ("Ab Aeterno")
In 2007, after Richard declared he was done listening to Jacob and left the beach camp, Hugo Reyes walked out to the shore and spoke in Spanish to Isabella. Jack believed Hugo was talking to Jacob and tried to question him, but Hugo merely walked into the jungle to track Richard, accompanying Isabella's spirit. Richard trekked far into the jungle and unearthed Isabella's necklace. Hurley had followed and alerted Richard that his wife was standing directly beside him.
Then as Isabella spoke words of comfort Hugo repeated them for Richard. Although unable to see her, Richard eventually felt his love's presence and tearfully spoke with her. Her final warning was to stop the Man in Black from leaving the island, or they would all "go to Hell". ("Ab Aeterno")
- The casting call described her as "[ISABELLA] Latina, 30s, fluent in Spanish. Strong sense of self and adores her husband. Devout Catholic who is battling a long-term illness...GUEST STAR." 
- The name Isabella means "My God is a vow".
- Isabella is not a Spanish name, but rather Italian; the proper Spanish way to spell it is Isabel.
- Isabella and other Spanish characters have a Latin American accent, not the correct European Spanish accent.
- Not to be confused with Isabel, the sheriff of the Others.