Answer:
A-She signed documents personally securing the debts of the business.
Step-by-step explanation:
When you form a business as a LLC that protects you from liability in case of debt when the business goes into bankrupcy, that protects the owner from having to put their properties as collateral for the bankrupcy, the only way in which your sister could be personally liable for her business debts is if she signed personally for the business debts.