Choose a character trait or two from the Cattell's 16 Personality Factors post.
For each trait make two lists. One, a list of ways that trait could be an advantage in certain situations. Two, a list of ways that trait could be a disadvantage. How has the trait helped her? How has it hinder her?
Whether the trait is positive or negative, there will be both advantages and disadvantages. For advantages of negative traits and negatives of positive traits you may have to dig into her childhood. How did the trait make her vulnerable? How did the trait protect her?
If the trait hindered her or left her vulnerable in her past, did she suppress it or hide it behind a persona? For instance, did she learn to lie because the truth was often punished? Did she learn to detach because those she trusted betrayed her? Did she learn early that kindness was a weakness and so became unkind herself?
A negative trait that gave her an advantage when younger, may be a hinderance now. But she'll cling to it because it worked in the past and it's become part of her identity. It's who she is.
Your job, as your character's
To dig a bit deeper there are three story possibilities for the character traits.
It's a trait your character was born with and currently is.
She will have arranged her life to avoid facing her weaknesses. She'll limit her wants to what her strengths can get her. She may have convinced herself that any want that involves her weaknesses she doesn't really want. Mine the disadvantages list for obstacles to throw at her. While this trait will always be a part of who she is -- an introvert won't stop being an introvert -- she can learn how to work with who she is, learn strategies to overcome the disadvantages.
It's a trait your character was born with but has hidden it behind a persona that's opposite.
Forcing her to face her weaknesses will be more than just uncomfortable. She will have buried her trait beneath layers of shame or feelings of weakness. The trait may embarrass her, or dredge up unpleasant memories. It may feel alien if the trait was unacceptable in her family or community.
It's the personality trait your character is pretending to be in order to hide her true (and opposite) nature.
You'll want to make her hidden nature necessary to get what she wants, but she won't want it to come out for the same reasons as above. The advantage list is why she'll cling to her persona. Her life will be built around the advantages. It's your job to take them away. It's your job to put her through the wringer of her disadvantages to get that most wanted thing.
Though this post works perfectly fine as a standalone exercise, the previous post on character development is Wrangling your character into story worthiness. The next is Characters with potential (will be posted on Friday).