Here is my take on this. If you are dead set on developing film in your kids school you are going to have to do it with whatever chemicals are already in the school otherwise it might take you forever to get approval to bring in new chemicals. Look over a list of what is in the school and if you can't process film with it your kids are going to have to process at home, it's a lousy answer but by the time you get developer and fixer into the school your kid might be in college.
Now making prints, that's another story, here in the states there is a product called "Sun Prints" it is basically pretreated Cyanotype paper that only needs water to fix it, you should be able to find a similar product in your area. The kids could use it to make contact prints, and as an added plus with Cyanotype process you can actually see the process happen. You can see the paper turn a lighter blue, then you can see the negative image on the paper when you remove the negative, and you can see the positive image form when you wash the paper. All you need is sunlight and water and you can have an archival quality print, if the kids don't like the blue images you can tea stain them using a mug of hot water and 5 tea bags. Make tea, soak washed cyanotype for 30 minuets in tea, wash for one minuet in water, and dry, now you have a B&W photo.
Best of luck to you.