I’m not sure… but since there’s no replies I’ll offer a possibility.
if you check out this tutorial here (which is quite easy and quick to go thru): A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums
It shows how to make a mini map by using a texture,material, scene capture. Perhaps you can apply the same concept using the texture on a scene actor(the mirror) or something and having the camera reflect the character in front of it.