OP again.... Have been crazy busy with work
I was beginning to think I had imagined posting this question because I hadn't,the been able to see it in the past 2 days...but to answer some questions
-whatsanenigma yes artificial sweetness can verify used, although they are trying to avoid them.
Well, here is what I would suggest, though it really has no name (it has been modified from a higher calorie version over the years) and my family just calls it "That Jello Stuff".
Basically, it's sugar free jello, plus sugar free cool whip, plus some fruit out of a can. The ratio is one box of jello to one container of cool whip to one can of fruit.
You make the jello, let it set about halfway, then stir in the fruit, then let it finish setting up, then stir in the cool whip. Don't stir it very much, though! The sugar free cool whip is very vulnerable to melting in a weird way if you stir it too much. Get the jello/fruit combination stirred up first and then add in the cool whip at the very end and stir it only as much as you need to.
One good combination is cherry or strawberry jello and mixed fruit. Another is orange jello and mandarin oranges. Either way, drain and rinse the fruit well before you add it, especially if the fruit is packed in juice instead of water. But you need to be careful not to let the fruit get smushed from too much washing.
Optional things to add are chopped nuts and mini marshmallows. Given the dietary restrictions you are working with, I would advise putting bowls of these to the side to be added if someone wants them.
This does keep well in the fridge but is best served as soon as it is stirred up.
Hope that helps! It sounds like you have quite a challenge on your hands.