Chad, it's not an easy situation. One of my best friends was in country for close to a year and no matter how old (he was mid 40's 2 mid teen kids) you are, it's tough.
The sessions with the psychiatrist will only help so much. Chances are he may put her on meds. If a suggestion can be made try not to have her put on any SSRI anti-depressants. My wife was on Paxil for a number of years and the side effects are almost as bad as the treatment.
That said, she'll need a support network just as she would need it while you on duty. If you could suggest and she's willing then have her try to find a group of service member's spouses who also are having to deal with depression and anxiety issues. There may be something from your home base that she could possibly get involved in.