Pretty sure we won't see the actual consequence of either choice until the game is completed. The main thing I know is it increases your relation (affection) with Ella if you don't rat her out. Idk if anything currently happens that changes dialogues or what not if you do expose her since I never give away stuff about her.
I'm sure there will be some type of decently sized change later on depending on the route you're going, by that I mean if you are truly against her or with her. I also don't know the affection numbers you need to get certain scenes (if it even works like that which I'm assuming so since...well they can increase or decrease) because I always have high affection with pretty much everyone