That she took out the loan herself is irrelevant - the relevant part is that it is marital debt that you are partially responsible for.
What she could do is forego suing you but bring a motion before the family court judge to mandate that you make payments.
In reality, this is a marital debt and should be decided by the family court judge as to whom owes how much of the debt and how the debt will be paid.
Then, if she gets a court order for you to pay a certain amount and she to pay a certain amount - then if either do not pay that amount - they can be brought before the court on contempt of court order and a request for sanctions be levied against them.
Too, the court realizes that they can't get blood from a stone - that you can only pay what you can afford. However, the court will make the determination as to what you can afford and spread those payments out. Clearly, the court also has to take into consideration what the loan payments are and whose debt made up a majority of the loan.
So, my advice to you would be to try and negotiate a settlement with her so as not to end up in family court before a judge and to draft an agreement reflecting what your agreement is - then everyone sign it and adhere to it.