Gina is an elderly woman who lives in Brisbane. She cannot speak or read and write English very well. Early this year she visited her bank, Wusspac, and signed documents which her bank manager, Ian, said were general papers relating to her savings account. A month later Gina found out that she had signed mortgage documents over her house guaranteeing the debts of her grandson and his business. Gina is shocked to find out the bank could sell her house to pay her grandson's business debts. She wishes to stop the bank. Advise how Gina can prevent the bank from enforcing the signed agreement. Use case examples and common law contract legal principles to support the analysis in the answer.

Do not discuss statutelaw.