Hi there, I'm a sufferer of cold urticaria too. I was first diagnosed with chronic idiopathic urticaria and years later, I found out that I had cold urticaria too. Sad to say, I have been living with it ever since. But taking antihistamines daily helps to prevent the hives to break out. I am already living in a warm climate, but it sure doesn't help! Every building nowadays are air-conditioned... that includes transportation, and many more.
If it's winter, let your daughter wear lots of warm clothings, take her medication regularly and have an epipen in hand. I'm not sure if her doctor has given her one but it is critical for people like us if we ever go into anaphylactic shock; it could give us some time before we reach the ER. I always take my jacket along with me wherever I go, in case the place that I go is air-conditioned. You could get a medic alert bracelet for her so in emergencies, the paramedics or doctor can refer to the bracelet.
Other than the cold weather, people with cold urt can even break out on warm weathers! For example getting out of the pool, the rewarming of the skin can cause a reaction. Never let your daughter swim alone and make sure she is wrapped up as soon as she leaves the pool. Btw, does she gets swelling on any parts of her body?
What medications are she taking? Did she has any blood tests done? How did the doctor diagnosed her? How old is she?
All the best to both of you! Let me know if ya need any help.