Jing-mei's identity is shaped not only by her early childhood experiences and her mother's parenting style but also by her mother's trauma prior to Jing-mei's birth. Jing-mei's mother fled China upon the Communist takeover in 1949. In the turmoil of the Revolution there, she lost her parents, her husband, and twin daughters. Jing-mei's mother dealt with that trauma by seizing America as her hope for a better life. She fiercely believed that America offered unlimited opportunity, and she pegged her happiness on her daughter's taking full advantage of the hope America offers. Thus, the trauma she experienced led her to adopt a parenting style that would shape Jing-mei's identity.
Jing-mei's mother's parenting style was, to say the least, pushy. She was convinced that Jing-mei could be a prodigy and become famous, and by constantly pushing her daughter, she made her feel like she was not important for who she was, but rather for what she could accomplish. When Jing-mei "failed" at test after test, her self-image plummeted. Since she couldn't meet her mother's ridiculously high standards, she decided to "act out" by putting in less effort than she might have otherwise done. She then blamed her mother for her failures.
Jing-mei's experiences shaped her identity as well. Being part of a society in which high-achieving children were the norm--such as Auntie Lindo's daughter Waverly--also spurred Jing-mei to go the other direction. She saw other children being made into commodities--being valued for their performance rather than for themselves--and she didn't want to take part in that way of life. Hearing her mother brag about her non-existent talents, Jing-mei "determined to put a stop to her foolish pride."
Interestingly, years later, after her mother has died, Jing-mei tries playing the piano again and is surprised at how quickly the music comes back to her. This suggests that perhaps she did have musical talent after all. But because she was pushed too hard, she chose to not pursue music in favor of being true to herself. Whether she overreacted or whether she was right in believing she had no musical ability is unclear. What is clear is that her identity, as she grew to adulthood, was shaped by her mother's past, her mother's parenting style, and Jing-mei's own childhood experiences.