There is no request for abatement I(except refund after fully paying) and perhaps there never was abatement being discussed since the cnc stands for currently not collectible.
Currently not collectible means that by IRS standards you do not have more than the income needed (by their standards) for living expenses. Collection is stopped but the tax debt remains when on that status and is not abated.
You can request an installment payment agreement and propose a monthly amount which can be done online when
If the amount is more than $50,000 or returns have not been filed you will need to file any missing returns and then complete and mail Form 9465, Installment Agreement Request . If you owe more than $50,000, you will also need to complete Form 433-F, Collection Information Statement
Whether or not you will once again be eligible for the currently not collectible status will depend on the information on the Collection Information Statement.
So, several possible moves for you are:
1) online installment agreement if available using an amount you can pay each month
2) paper Form 9465 and Form 433-A if not using option 1
3) confer with a practitioner experience in collection and audit representation if you are not comfortable doing either option 1 or 2
Option 3 may also be most proper if you are trying to say that only she is liable for the debt (also known as innocent spouse relief) which can be similar to abatement. The details and facts needed to determine that are best presented to a local practitioner. For more on that topic see http://www.irs.gov/Individuals/Innocent-Spouse-Questions-&-Answers
If you decide to apply for innocent spouse relief on your own (though that is not what I would recommend) then consider using option 1 or 2 immediately to stop any potential collection action.
Please ask if you need more discussion or clarification.