Congratulations! Being a very old Primary President of a very large Primary (we have a dependent branch and I have 160+ kids on my rolls; 100+ there every Sunday) I have several reverence tricks. In a Primary your size, back when I had a Primary your size, I used to be sure that Sharing Times involved a lot of getting up, such as games on the board or marked in masking tape on the floor or flannel board stories (works best for the little ones if you have a split sharing time). We used (still do) a pick jar with kids names so that everyone got a turn, not just the eager beavers. One trick that works very well when we're having an extraordinarily bad day is to pick a name, look at it and say, "Oh . . . I'm sorry. This child isn't being very reverent today - we'll have to pick another." Obviously, the kids can't see the names and we, of course, don't mention any names. Generally speaking, it doesn't matter whose name is on the stick - we're going for general reverence, NOT singling out any one child. We also have sticks that say, "most reverent", "listening carefully", etc. so that we can pick one who's trying really hard sometimes.
I have a wind-up music/jewelry box. I wind it up partway before Sharing Time and if it gets noisy, I open the box and leave it open until it gets quiet(er!) The box is full of stickers and if there is music "left in the box" at the end of Sharing Time, everyone gets a sticker.
We have a mail box for the end of Sharing Time. We use it for talks, scripture, prayer assignments but it's also used for reverence awards. Our Primary is so large that we have one Reverence Certificate for the "most reverent" but also big stickers that say "Awesome", "Neat", "Amazing" and choose a child from each class to get the smaller ones, too - otherwise it takes too long to get a recognition of some kind. The kids from each Sharing Time who receive a certificate get to be our "Reverence children" for Sacrament Meeting - they stand on either side of the podium with their arms folded to be an example. The Bishop always thanks them by name and shakes their hands. It's a big deal - even our Sunbeams want to do it, although mom or dad usually stands with them. Since you have a smaller Primary, you might could choose a boy and a girl or pick one older and one younger child. Our Secretary chooses the children and keeps a chart in her stuff so that we can catch even the most reverence-challenged child doing something right - everybody eventually gets a chance.
