If your mother's parental rights were terminated, it is unlikely the court will find that living with her is in your best interests. Until you are legally considered an adult, the court has a responsibility to judge whether you should live with your 'real mom' based on your best interests. Since her rights were terminated in either your or a sibling's best interests, the court will probably not change its position.
You need to speak with an attorney experienced in juvenile and/or family law.
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