1) Someone with a POA does not have the right to be notified of their principal's (the person giving them the POA; i.e. your mother) transactions or financial arragements.It is also not illegal for someone to make a bad decision or do something which is a bad idea for them, so long as they are mentally competent (see below).2) If you mother is not mentally competent--which would require a determination of incompetency by a court, made on medical/doctor testimony and evidence--then any agreement she enters into when she is not competent can be set aside (voided) for lack of capacity. If she does enter into such a loan and you believe your brother took advantage of her, you may need to bring a legal action to have her declared incompetent and have yourself appointed as her guardian. Speak with an elder law attorney about his.3) If she takes out the loan and it is not set aside, then if she passes before it is paid off, the lender would have the right to foreclose on her home, sell it, apply the proceeds to the outstanding balance, and then return any remaining amount to the estate/heirs. It may be possible for the estate or heirs to work something out with the lender, under which they will pay off the loan and the home will not be foreclosed.4) If she passes, the loan would be a debt of her estate, and could take up assets which would otherwise go to her heirs.