can a collection agency take up your house if you don't live in the states?

ok this is quite complicated. My mom's friend is having serious debt problem and she can no longer afford any of her bills. she's never worked, her husband does for the past 20 something years. she's seriously ill- her medical bills are surpassed above the millions i believe. anyways, her husband is a sore loser (he gambles alot) and so therefore they don't have any money. they owe alot on credit card (all by her husband) and they just cannot keep up w/ mortgage payments. here's the problem- she's planning to stop paying the credit cards altogether because the credit is already messed up and she cant afford even the minimum payments. the cards are under her sister's name and the house she lives in is under her sister's as well. if she stops paying the credit card-obviously it will go to a collections agency but do they have the power to take up the house? she doesnt worry about the credit but she doesnt want to be homeless. her sister lives overseas and will probably never live here.