Flora has just reopened her business after a long closure occasioned by a compulsory lockdown. Her business is struggling financially and she approaches her bankers, Easy Money Commercial Bank, for a loan. Easy Money tell Flora that they are unable to provide further loans unless she can provide additional security. Flora remembers that her grandmother owns a large home. She tells the bank manager, 

Penny Moore, that her grandmother will provide the home as security. Flora has not discussed this with her grandmother. Penny accompanies Flora to her grandmother’s house to get her to sign the loan security documents. Flora’s grandmother has not had any experience in business and has never had to deal with a banker directly. She is also not able to speak English well as she moved to Australia from Sweden forty years ago and has never bothered to learn the language. She does not understand the documents that are presented to her by Flora and Penny. 

They explain that the documents are a guarantee to allow Flora to get the loan and that everything will be fine. They assure Flora’s grandmother that she has no need for independent legal advice. The documents are actually a standard security guarantee, which will allow the bank to foreclose if Flora does not pay. Her grandmother signs the document and Flora receives the loan. Flora’s business does not improve and within a few months she defaults on the loan. The bank attempts to foreclose on the loan and seize her grandmother’ home. 

Explain to Flora’s grandmother the ground under common law and statute that would allow her to void the guarantee for lack of consent on her part.