i understand how life changing it is to have loved one (my son) on a special diet.--it also has the potential to bring so much healing because this knowledge is such a powerful gift to be able to help control someone's health in such a do-able way.
i never told my son that he had to be deprived or that he was different--i said 'we are dang lucky to know what can help you, dude'. so he was prevented from majoring on the negative aspects of his special diet--like at parties and things--your choice, wannabe sick or wannabe healthy. done.
my suggestion is to keep this as matter of fact as possible--just a thought--
fwiw-- i might have a few recipes in my weight loss blog www.k8memphis.blogspot.com--the flour free peanut butter cookies might work for her--and if they offer some kind of non-dairy butter substitute the chocolate cups and brownies might work too--
and one other thought is to maybe go for the teeny tiny small amounts like in my recipes using 1 egg or even half eggs --at least it's an option sometimes to make her small special treat when the others are having their brownies etc.-- saves on those pennies -- i get it --
so you can do this--no it's not easy---and once you get out of the woods here and get a few recipes rolling well--you'll all do great--
plus i got a flax seed muffin thing and a zucchini bread that's killer--i'll get them onto my blog right away tomorrow sometime--the muffin cooks in a minute in the microwave--easy peasy! and versatile