Typical elementary graphing questions include questions like:
- What color is your hair?
- What color are your eyes?
- What is your favorite season?
For younger kids, you could give one sentence daily, or you could give them several. You might have them actually survey family members each day, graph the result and then write sentences like, "My mother has brown eyes" or "Three people in my family have brown eyes."
At any rate, if you just need something quick to get a younger one writing, these can be very helpful, in shaa Allah.
I found an extensive list of graphing questions at CanTeach: