I always do this. I LOVE voting, always have and always will. Dropping it off in person is a joy for me. I always would take my little dogs to the polls and they were given I VOTED stickers (all of their stuffed animals still have the stickers on them).
I taught my 1st graders the voting process and we voted all the time for everything and it was all done by them, not me. I would also take them on a "field trip" every year to the polling area in the cafeteria. They were as quiet as mice, polite, listened and asked good questions. The people working at the polls would give them a mini-lesson and they thought my kids were so cute. In class they chose the topic, the options, and passed out slips of paper. They had their "privacy boards" up (no peaking) and they voted anonymously. They collected the papers, they tallied the votes and they got to have 100% control of all of it. I just sat amd observed. We'd vote for what game to play at recess, what topping should go on the pizzas at our class parties, etc. I gave them I VOTED stickers in 4 languages (my classes were multi cultural).
I still write to former students and they remember these lessons!