Eggs, of course, are naturally gluten free, but you be concerned about the dyes that are used to color them. Here is an article showing how to color eggs using natural ingredients such as oranges or lemons. Since the only other ingredient involved is distilled vinegar, there will be no problem.
I could find no information about commercially-prepared dyes. I have examined a label from a McCormick product and seen nothing inappropriate. Click here to read my article on the subject.
Another alternative is to fill the Easter basket with things like yo-yos, magic markers, marbles and other items that are attractive but not edible. Click here to read a list of possibilities. Keep the list. You can use it again on Trick-or-Treat night in October.