Does foreclosure mean they can take other properties from you??

The lender can only foreclose on the house that they have a mortgage against. They cannot take any other property in the process, however, if they cannot get the full amount of their loan back through the foreclosure process, they can place a lien against your mother-in-law for any amount that they cannot get back (plus penalties and interest). If they do, that lien will enber her current home.