lovemygirl,
If I read your post correctly, last year there were 2 families (including yours) that had cf kids. You knew who the other cf family was then and so you talked to the other mom and the two of you agreed to keep your kids in different schools and to facilitate that you moved Ashley to a different school. Since then a new family with a cf kid has moved into your town and there are now 3 families with cf kids in your town (including your Ashley). The parents of this new cf kid did not contact either you or the other cf parents before they enrolled their cf kid in school. They just enrolled him/her into the school they thought best (unfortunately for you the school that Ashley attends). So even with your best efforts there is Ashley now attends a school that has another CF kid attending as well. Right?
There seem to be 3 parts to your query. 1)Should CF families who have kids attending school be in contact with each other and make joint decisions about school enrollment based on their kids illnesses? 2) Should what school a kid attends be determined by the objective of having only one CF kid per school? 3) If there is more than one cf kid attending a given school, what should that school do to decrease the chance of cross contamination?
As far as #1 goes, I don't believe that one family with a sick kid has to talk to all the other families of sick kids when they are making decisions for their sick kid. A family's responsibility is to their own kid - making a good decision for that kid is hard enough without worrying about everybody else's kid. (And I say "sick" kid rather that cf kid, because as others have pointed out, it's not just cf kids who have to worry about contagious diseases more than other kids - kids with suppressed immune systems for any reason have to worry about this.)
As far as #2 goes, I think that where a kid attends school is a decision made by parents based on a multitude of things. It has to do with location, or curriculum, or teachers, or values, or student/teacher ratio or whatever as well as # of sick kids attending.
As far as #3 goes, I think that the separate classrooms and separate equipment (when small) is about as far as you can expect a school to go. Clean gym equipment is an issue for all of the kids in the school. Obviously they can't sterilize it between classes, but it is a darn good idea to wipe it down from time to time - and if one of those times is between usage by CF kids, well, so much the better, but I wouldn't make an enormous issue of it.
Even so, I hear and feel your frustration. Obviously having Ashley being the only cf kid at her school is obviously very important to you - important enough that you transfered her last year. I don't know how many schools there are in your area, but if there are 3 then I suppose you could transfer her yet again to the school without any cf kids (at least as far as you know). But transferring her could get old real soon and sooner or later you aren't going to be able to keep her in her own school. Typically by highschool all of the kids are together and even keeping them in separate classes gets tough (particulary if 2 cf kids want to take something like Russian 4 the same year or something). Eventually, Ashley will need to learn how to take care of herself in a world full of folks with contagious diseases and low immune systems.
So I'd suggest taking a deep breath and focusing on teaching Ashley the tricks of the trade for avoid infection now (without making her entirely paranoid). Keeping her distance from folks who are coughing or sneezing, washing her hands frequently, wiping down common surfaces before she uses them, etc. Of course, she's too little now to really be on top of all of this, but if you point out these things to her teacher then maybe her teacher can be the one on top of it in the school for now and the teacher can help Ashley take these steps.
Good luck to you. It's scarey I know. Part of you must just want to keep her in a bubble. But I bet that most of you wants her to have a wonderful school experience at the school that is the very best match for her.
Keeping you in my heart,
LisaV