I seriously doubt the intent of giving her a disability retirement separation is to ensure she also gets charged with the offense of fraudulently obtaining her discharge.
MANUAL FOR COURTS-MARTIAL UNITED STATES (2005 EDITION)
Rule 202. Persons subject to the jurisdiction of courts-martial
Courtmartial jurisdiction over active duty personnel ordinarily ends on delivery of a discharge certificate or its equivalent to the person concerned issued pursuant to competent orders. Orders transferring a person to the inactive reserve are the equivalent of a discharge certificate for purposes of jurisdiction.
(B) Termination of jurisdiction over active duty personnel. As indicated above, the delivery of a valid discharge certificate or its equivalent ordinarily serves to terminate court-martial jurisdiction.
( d ) A person discharged from the armed forces who is later charged with having fraudulently obtained that discharge is, subject to the statute of limitations, subject to trial by court-martial on that charge, and is after apprehension subject to the code while in the custody of the armed forces for trial. Upon conviction of that charge such a person is subject to trial by court-martial for any offenses under the code committed before the fraudulent discharge.