My mother is being sued for credit card debt. Can she and how does she demand a jury trial?

A breach of contract, which is what she is being sued for, is usually not heard by a jury. Never ever ever ask for a jury just for purposes of appealing to their sympathy. That is a big mistake.

Sounds like a civil case to me. Mom needs a lawyer to defend the case and request a jury trial. If she's being prosecuted, she has the absolute right to a jury trial.

In some counties, at the time an Answer or other Responsive Pleading is filed, you must state that your Request for a Jury Trial within the document. Also, make sure to pay the $150 fee at the time of filing - although technically the fee is not required at or before the date first set for a Case Management Conference.