Dairy Allergy?

I think Emmie might have a dairy allergy.
At first I was leaning more towards chocolate, because she always spits up after she has chocolate. But last night, she had ice cream, and that came up too. I wonder if it is the milk in milk chocolate.
Interestingly, cheese doesn't do this to her. But it could be because she doesn't ever consume enough cheese. She drinks soy milk, so I don't know about regular milk. I'm going to buy some soy ice cream tonight and see if anything happens. Maybe it's sugar!