Brittany Miller is the lead singer and leader of the The Chipettes and is the female counterpart of Alvin. She is the older sister of Jeanette and Eleanor. Her last name is Miller in the 80's cartoon, but she does not have a stated last name in CGI. It is presumed to be Seville because of The Chipettes being adopted by Dave.
Brittany was the first one born of the three Chipette triplets in Australia. All of them were orphaned, but it wasn't mentioned in the series. Luckily, they were taken in the care of by an orphaned human girl named Olivia in an orphanage, until they were kidnapped by Miss Grudge (the runner of the orphanage) and Eva (another orphan). The night when Olivia was adopted, the Chipettes all escaped 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 after working at a restaurant.
At times, Brittany has been shown to be impulsive. However, she drives toward any goal she has set with complete determination, stopping just short of ruthlessness. During the series Brittany is depicted as domineering and as somewhat sarcastic and untrustworthy. An example of this is when she dismisses Simon's advice in The Chipmunk Adventure, when he advises them to avoid the easterly route to avoid a hurricane. She believes it to be a trick to slow them down so they'll 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 the hurricane. Her sisters demand that she admits her mistake, however as she is trying to admit it, she is unable to say the full sentence, instead changing the subject. However, Brittany is shown to be 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.
Brittany has been shown to be vain about her appearance. In I Love the Chipmunks Valentine, it is shown that 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 forward speaker for her sisters.
Alvin and Brittany have always shared an on / off relationship, often appearing to hate each other. However, they are known to express romantic feelings towards each other. The common scenario between the two is that at first they appear to be friends, but eventually butt heads, argue over the subject for a period of time (often blowing it out of proportion). Despite how bad things get, the two eventually agree that they care for each other and make up.
Though her basic concept is retained in the CGI films, there are some notable differences. Besides appearance, her personality is toned down. She is a lot friendlier and polite, making it easier for others to approach her. She is nicer and has better control over her temper than Alvin does, though it is still a bit shorter than most. She is also shown to have a much better, loving relationship with her sisters, becoming visibly concerned and defensive about them when her manager Ian tried to split them up. Unlike her cartoon version, she is able to apologize when she has judged wrongly.
In Alvin and the Chipmunks: Chipwrecked, her personality is a mixture of what she was like in the 80s and what she was like in Alvin and the Chipmunks: The Squeakquel. Sometimes, she and Alvin have hard times with each other, but they truly care for and appreciate each other.
Jeanette isn't brave enough to stand up to Brittany. Brittany pushes Jeanette around a lot and takes advantage of her kindness, but deep down they love each other very much and are very loyal to each other. Brittany gets very defensive of Jeanette when someone else is mean to her, in most situations.
Eleanor always stands up to Brittany when she tries to push Jeanette around, and is generally the only person that tries to stand up to Brittany(besides Alvin). The two of them do share a very nice sisterly relationship.
Alvin and Brittany have a very competitive relationship. They are constantly at odds with one another and fight, but they do show that deep down they love each other. They are shown in the future as married with twin boys.
- Brittany is very similar to Alvin: They are the leaders of their respective groups, very competitive, enjoy extracurricular activities, often the most outspoken, stubborn, arrogant, selfish and conceited. Their unwise decisions or "spotlight" personalities commonly are the cause of many mishaps and adventures. Despite their selfish interests, they usually come through for their siblings in the end.
- Brittany "hates" green and never really takes the time to realize her younger sister Eleanor wears green. However, Eleanor doesn't seem to be offended by this statement.
- Brittany is nyctophobic or afraid of the dark.