Thank you for your question today, I look forward to assisting you. I have nearly 20 years of legal experience in various disciplines, including JAG.
Ok, first off, she is not "entitled" to anything.
Nothing in the law requires that the court grant here even one penny of your military retirement. The court has wide latitude to do as it sees fit with regards XXXXX XXXXX retirement. So, unless and until a divorce court specifically states in a divorce decree that you owe her, you do not "owe" anything.
That being said, it is possible for a divorce court to decide to grant her a portion of your retirement. In that case, while it is true that DFAS will not pay her directly that does not mean that you would not then owe her the funds. If the court grants her a percentage, then you need to pay it. If you don't, you will be in contempt of court and the attorney can use the powers of the court to garnish those funds, your bank account or even jail you for not complying with the court order.
But that is only true if you actually retire. When a court orders that you owe a portion of your retirement, you only pay if you retire, so if you ETS before you retire, then she gets nothing, even if she was awarded a part of your retirement.