Brittany has at times been shown to be impulsive but has also been shown to drive toward her goal to a further extent although she stops short of ruthlessness. During the series Brittany is depicted as domineering and is shown as somewhat sarcastic and untrustworthy. An example of this are when she dismissess Simon's advice in The Chipmunk Adventure, when he advises them to avoid the easternly route to avoid Hurricane Arlene, believing it to be a trick to slow them down so they lose the race. Also due to her ego Brittany has been shown to be unable to admit her mistakes. Such as when her balloon is destroyed as a result of being caught in a hurricane her sisters demand that she admits her mistake however as she is trying to admit she is unable to say the full sentence as she is unable to say the word wrong. However, Brittany is shown to be at times kind and compassionate such as when she at first refuses to help Eleanor take home a kidnapped baby penguin but later submits after seeing its deep sadness and longing. Also Brittany has been show to be more vain about her appearance. In the "I Love The Chipmunks Valentine," it is shown several boys wanted to go to the dance with her (although she only wanted Alvin) which means she is seen in boys eyes as "attractive".
Like Alvin, Brittany has always taken on the role as leader of the Chipettes, being lead singer or foward speaker for her younger sisters.
Brittany and Alvin have always shared an on/off relationship, often at times appearing to hate each other, however they are known to express great feelings of love towards the other.
The common scenario between the two is that; at first they appeared to be friends, but eventually butt heads, argue over the subject for a period of time (often blowing it out of perpetration), however despite how bad things get the two eventually agree that they care for the other and make up.
In the series Brittany was the first one born of the 3 Chipette triplets in Australia. All of them we're orphaned, but it wasn't mentioned in the series. Luckily they we're taken in the care of by an orphaned human girl named Olivia in an orphanage, until they we're kidnapped by Miss Grudge (the runner of the orphanage) and Eva (another orphan). The night when Olivia was adopted, they all escape to New York where they worked as miserable diner waitresses and lived on the streets. Until a few years later they moved to California and eventually hit the big time.
In Little Alvin and the Mini-Munks they live with Dave and The Chipmunks. And at early age she pronounced words wrong (EX: lippick = lipstick, Gilda = Gila, Nette = Jeanette). It also appears that she developed her personality at an early age, for instance she seems in Little Alvin and the Mini-Munks she seems to be self-centered despite being very young. It also appeared that she did not develop feelings for Alvin until years later, as in the movie she shows no interest in him.
In short, Brittany is the leader of the Chipettes, and the love interest of Alvin. She is the eldest of the Chipettes.
She has auburn hair which is seen in a stylized ponytail with light pink ribbon, blue eyes, and her signature color of pink. In Rio film series, she wears a light pink leather jacket with light miniskirt. Finally, she wears a pair of matching light purple stockings that reaching her upper legs and light pink leather boots that end just below her knees, along with a light purple ribbon. Most importantly, there also seems to be a light purple ribbon dangling on the back of her light pink leather jacket. But in some Japanese anime fan-arts, she wears a high light pink leather boots that reaching her upper legs.