I think this is an interesting concept, but I believe that the photo/avatar meme is acting as a facade and over-simplifying what is taking place; by tapping on a photo, you are initiating a conversation with a parent. You’re not done. Most likely the parent is going to want to respond with something more than an emoticon. They want to talk to you, they want your time. They want to know why there’s a referral, what they can do about it, and maybe give you some backstory to explain the student’s behavior. Parents want context and qualification of the message.
I’m a product manager, and my wife teaches high school — 175 students to be exact. We talked about this product, and we agreed that the more times you use this app the more time you are going to have to give up in “qualifying” what you said electronically. This app probably works well for smaller classes, and would benefit from having standardized sentences that lack ambiguity — something to avoid that time suck. And maybe have a parental role too allowing acknowledgement of the message — or more likely, a request for a callback.
Best of luck with the app! And get feedback from your customers!