Well it's going to happen to both me and my DH this year. He's teaching DS and I'm teaching DD! Probably would have wanted to avoid it, but wasn't possible with timetabling constrictions. I can only speak for myself, but can assure you as a parent that I will be consciously trying not to treat her any differently from her peers.
That must be really tough on both you as a teacher/parent and your kids. Had you considered sending them to a different school or working in a different school? I know some independents offer large teacher discounts if a child is at their school, so I can understand if that was an option. Do you think it will it only be for one year?