In my book, Raising Vegan Children in a Non-Vegan World, I recommend to families who are trying to switch from dairy to non-dairy to start with the things that aren't that noticeable.
For example, I wouldn't give her cereal with non-dairy milk just yet because the taste change is so dramatic. I would start with non-dairy waffles, pancakes, bread for toast, soy yogurt, oatmeal with non-dairy milk, etc. In these items, she isn't likely to be able to tell that she isn't eating cow's milk.
also, vanilla soy milk is meant to be a sweet milk. I only use it for baking. For foods, use regular rice or soy milk. Buy enriched for those great vitamins.
And maybe instead of butter, switch to non-hydrogenated margarine for a while. Like Earth Balance.
And if you're doing this on a trial basis, maybe also try eliminating cheese for a time and see what happens. Just make other things that don't contain cheese.
Anyway, I'm not saying you need to switch everything, it sounds like you don't want to switch everything... but I think it's often easier to use non-dairy items than people think.
Good luck in any case!