My father recently died and left my mother with over $80,000 of credit card debt. There are sufficient assets to cover the debt, but just barely, and not without tax penalties. She would be left with virtually nothing.
The late fees are continuing to mount, and all the of interest rates have gone way up. There is not enough cash to make payments without liquidating assets, which takes time. My father was 79 and continued to work until the end, but now the only income is social security. What is the best thing to do to stop the bleeding and help her in this situation? Any advice would be appreciated.

Seek a professional credit counselor - can be found in the yellow pages. Credit card companies are often open to reasonable negotiation for settlement in extenuating circumstances.

Good luck!

You did not say what assests they have ?

Basically in most areas they can't put a lien on their home. ( unless the credit card were used to make house payments or major improvements on the home)
And even then, it is just a lien, they can't force a sell, theywould only get their money when the house sold.

The worst they could really do if she tells them to jump in a lake is get an garnishment on her paycheck if she is working. ( not social security) and attach any money that is in any bank acount with her name on it. ( they will often do joint accounts, or freeze joint accounts till ownership of the money is proved) We have discussed here before if it is legal to attach these, but it happens anyway to a lot of people.

Now she will need to have the social security ( assuming that is her only income) to stop any direct deposit, and mail the check, thus not having money in a bank account.

But you need to discuss this with an attorney more than a credit couselor at this point with her age and situation.

Most likely except for trying to attach bank accounts, there is nothing they can do ( they will lie and say theywill put her in jail and more. But most likely they can't do anything at all if she just stops paying. But speak to an attorney to be sure in your state and depending on what she owns.

Were the credit cards debt joint accounts? If so she will need to contract an attorney, to help reduce the debt load. If they were not joint she still need to talk to an attorney.