Tattoos with your kid's names. Could be made smaller, placed in a more indiscreet area and perhaps with a bit of color... just a few ideas.
If I ever wanted to get a tatoo, I'd get something like this with my Emma's name. Love it! Custom Infinity Tattoo Design with Personalization
like the place of this tattoo... And its also an excerpt of One of the First Bible scriptures I memorized as a young lady. loved the placement.