Thanks for that affirmation. I actually taught them binary counting too over a weekend a few months back...I was amazed how quickly they were able to pick up on it (3rd and 5th graders). With limited time/energy, I was hoping to find some great resources to add to what I can provide them individually.
Look for opportunities to expand what they're doing in school. For example, after my kids had covered place values in school, I taught them binary. Their knowledge of base 10 is so much more robust when they learn base 2 as well.
Point is, I bet you already know plenty to be that ideal resource you seek for them. Good for you for wanting to start early.