disown (someone's) past

Translations
отрекаться от (чьего-то) прошлого
She tried to disown her past and start anew.
Она пыталась отречься от своего прошлого и начать заново.
Definitions
To reject or refuse to acknowledge someone's previous actions, behaviors, or associations, often implying a desire to distance oneself from those aspects of their history.