Are you one of DD’s teachers, OP?
In which case I think you will find that your real objection is not that she eats cheese on toast (actually, more often, due to lack of time, cheese with toast) but rather the nature of the cheese. I can’t help that she is a strange child and loves cheese so obnoxiously stinky that I won’t let it in the fridge, but I do apologise for her breath....
If you prefer, she could revert to her previous favourite combo of cheese and salami......?