It does sound like an allergy and allergies can be weird. I would still call the doctor tomorrow morning and just ask to talk to a nurse. Rashes can be caused by all sorts of things. You don't necessarily have to take your daughter in. but I always say better safe than sorry. I am not a huge lover of whole milk. Nobody in my family digests it. I'm wondering if your daughters stomach is upset as well. You might talk to the nurse about milk alternatives, and I am a big believer in probiotics. Has your daughter been on antibiotics? Antibiotics can cause all the same symptoms as milk allergies, and probiotics will help get her tummy back to normal. Just another thing you may want to run by that nurse.
Enjoy your little doll. They grow up faster than you can know!