Thankfully, once she deploys, they will have near-zero visibility into what she does - we can almost never get her to call us, much less her grandparents.
I appreciate the suggestions, and will pass them on - mom's been on him about 'poking the bear' with some of his more politically touchy posts, so this may get him to shut it down.
The photo is one she posted of herself, from her unit's informal photo pool on their public Facebook page, so no concerns with it - it's been vetted as safe, shows not much other than her, a large weapon and a brick wall, and has no identifying details that would be a concern.