Dress problems

My class of four year olds are graduating preschool on Friday and as their teacher, I will be attending lol. I got this dress thinking it was cute and I might be able to get away with wearing it to a pre k graduation. I think it might be too short. It comes about 2-3 inches above my knees and I’m 6ft tall so above my knee is pretty High up haha. So I added leggings and I think I look like a grandma. How do I make this dress look fashionable (I’m 20 not 90) but still appropriate for the occasion. Help!! Also looking for shoe suggestions I only own black ankle boots and they did NOT look lmgood with this. I was thinking flats? For should it be strappy sandals?