Biography
Life leading up to The Sims 2
Both sisters are romantically involved with the engaged town womanizer, Don Lothario; apparently each without the other's knowledge. Both Nina and Don have memories of having known one another as teens. Nina starts the game unemployed; she had a job in the Slacker career track, but did not manage to keep it long. She has long red hair and wears a black halter top with pink cargo pants, though when the game starts, she is in her swimwear, a blue bikini. Nina is presumably the elder twin, as in both twins' memories, Nina always grew up first. Her mother died when she was a child and her father died when Nina and Dina were adults. When the family is first played, she and her sister are 28 days from becoming elders.
Nina and Dina are the daughters of Flamenco Caliente and Nighat Caliente (née Al Mahmoud), now deceased, both also of Pleasantview. The sisters are also part alien in their paternal lineage (¼ Alien, ¾ Sim): their grandfather, Nestor Caliente, gave birth to their father, Flamenco, after being abducted and impregnated by Pollination Technician 7, making him their grandfather. She and Brandi Broke are not friends, but their relationship isn't far short of that level. Also, if she catches her sister with Don, her relationship with Dina can be mended quickly, however it may take some time with Don.
She is very interested in money, fashion, and traveling, and is said in her The Sims 3 biography to be a worldly sim who is up for adventure. She is also said to be the brains of the operation.
The sisters are both of Arab descent on their mother's side, corresponding to her former name Al Mahmoud. They are of Spanish descent on their father's side. Despite being one quarter alien, Nina and her sister lack any genetics for the alien skin tone. There is a chance that Nina, Darren Dreamer, and Brandi Broke will appear in the welcome wagon in The Sims 2 early in the game, since they are unemployed.
The Prima Official Game Guide for The Sims 2 base game features a comic strip-style tutorial chapter revolving around the lives of three CAS Sims living in Pleasantview. One storyline involves a married female Romance Sim engaging in an affair with Nina, who is also shown to be involved with Don Lothario. Based on this, some players choose to regard Nina as bisexual, despite the fact the game guides are not really considered official.
Life leading up to The Sims 2 (console)
In The Sims 2 for consoles, Nina is the brains of the two sisters. She someday wishes to study medicine but is not employed. Like her sister, she has the romance aspiration.
Life leading up to The Sims 3
In The Sims 3, Nina appears in the downloadable neighborhood Barnacle Bay, along with Dina. It appears that they moved there after Pleasantview. When the game begins she is at level 1 in the Sports career. She starts out with 10 skill points in Charisma and 8 in Writing, which would make her a good candidate for the Communications major if The Sims 3: University Life is installed. If The Sims 3: Late Night is installed, she and her sister are 4 star celebrities.
Nina has the Super Popular Lifetime Wish in The Sims 3. This is somewhat odd, as it doesn't match the Romance aspiration she had in The Sims 2, though the Flirty trait does give her romantic tendencies. Her portrayal here also contradicts that she was very shy and serious in the original game, the opposite of her sister in personality, while here she and Dina have almost the same traits.
In The Sims 2, she and her sister are involved with the same man, and in The Sims 3 they are involved with the same men: Alec Trebo, Juan Jr Inkbeard and Jeff Smith, causing some tension in their household. Her appearance is similar to what it was in The Sims 2, though now she has a slightly different hairstyle and a different outfit.