If you have an agreement in writing or a court order allowing 10 days grace period, tune out the ex. 12(b)(6) is your friend. If a garnishment suit is brought, at her expense, you can request and will probably receive a summary judgment based on failure to state a claim upon which relief can be granted (Usually rule 12 (b)(6) in rules of civil procedure). Even if everything she states is true, so what, she still loses if you did not violate the agreement.
However, if you make being late a habit, she may very well be successful in going to court to get the order changed.
Every legal matter is fact specific, and there are often nuances in every case. This is intended for comment only, and does not create an attorney client relationship.
I see nothing in here which would allow a garnishment. The payment was made, meaning it cannot be the basis for a garnishment. One late payment will be insufficient for a modification of spousal support to allow for some other process to collect support as it becomes due. Just don't let late support payments become a habit.
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