HI Marlene,
I transitioned a little bit over a year ago, and really did not make much of an issue about it. The only people we have told at the schools have been my child's direct teacher. We did not inform the school, as there is no need for anyone beyond the teacher to know anything. So far we have done this with two teachers at two different schools, pre k and then K. This year, just due to new school construction we will be at yet another school, and may not even say anything this coming year. My child has not faced any problems at all, and no issues have come up. As for other parents, the parents we knew before we still know, our children still play at each others houses. But we were straightforward about things, and we did not make a big deal about anything. Keep it simple, you don't have to involve too many people, of course this can also depend on the ages and how long your children have been going to the school, etc. But this has been my experience.