Skin test are not 100% accurate. Did your daughter have any
antihistamine in the previous few days? that would also negate a
test. Most allergists are primarily environmental based, and know
almost nothing of food allergies and sensitivities. Possibly the
allergies are more of the delayed type, that doesn't show up on the
scratches.
Some allergies develop over time, while others diminish. Test every
new food for a few days before you give it a full go- ahead.
Sugary foods give skin rashes that are not allergy- related. Maybe
the acidity of the tomatoes does that, too.
I'd keep Katelyn off the milk, soy, choc, and tomatoes. IT's better
to have a healthy kids. There's many foods still out there for her to
eat, you just may have to be making it from scratch.