So, I decided to make a box cake because it really doesn't have that much more milk or egg in it; and odds are she might not touch it at all. Also, part of this decorated cake has cupcakes, and I think I might use a different recipe for the cupcakes (or even make muffins that I know she's okay with) and give her one of those instead of the cake. I bought Pillsbury frosting and don't see any milk products listed in it. I made frosting last year, but it took so long to make. I think it will be okay. I will update this (with photos) early next week. Wish me luck.
A little update
3 years ago