All I've got is advice; some of this assumes they are leaving a bad situation.
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gather all documents (SSN card, birth certificate, bank statements or bills with their name on it, receipts for anything expensive they may be taking with them, etc).
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if they have money in a bank but the account is associated or linked with a person that may not be trusted, open an account at a new bank/credit union, withdraw funds from the old account, deposit in new account.
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if their phone (assuming they have one) is under someone else's name, it may get shut off without notice, possibly maliciously. If maliciously, cops might be called depending on how malicious. Same for any other items they take with them that might be expensive.