My sister is getting foreclosed on… how do I help her?

Pretty much as the title says, how can I help her? She has been served official papers.

We are in the state of WI in the USA.

She had a mental breakdown and is hospitalized and unable to work. It seems she hasn’t paid for quite awhile.

What can I do to make sure the house isn’t taken from my family? I’m not super rich, but I do have some liquid funds.

We can’t lose this house, it’s been in our family almost 20 years.

Thanks for any advice offered.