Dina is the youngest of the Tribbiani Sisters. Joey described her as his smartest relative of his entire family, she took the SATS and did two years of college, but still isn't terribly bright. At one point, she asks Rachel, "Do you ever worry that you'll be walking and your baby will just slip out?". As of 2001, she had sex with her boyfriend, Bobby Corso and got pregnant.
When Dina discovered she was pregnant, she went to Rachel first, asking her to help her tell Joey. Dina says that Joey is her favorite guy in the world and that she was more scared to tell him that she was pregnant than anyone else.
In the official subtitles, Dina appears as "Deena", but in the credits, is correctly written as "Dina"