Kudos to you for taking on your granddaughter while your daughter is serving overseas.
I won't ask about the father's responsibilities, here.
I listened to my mother. she said DO ANYTHING you can think of to not be drafted & go to Vietnam. In 1963 I was called to report, but I flunked my pre-induction psych physical. I used my position of only child. Sole son, and my acting skills - to be disqualified. Consequently, I was not drafted, finished my college education with average marks (except in drama, English, and communication TV & Radio) for the required courses I didn't care about.
I was a hippie, coffee house, folk singer/actor in the '60's.
Then got married in '67 & raised family #1.
In '79 I divorced, and in '84 started family #2.