Hello.
Thank you for asking at HCM.
There are many causes of 
hives. 
I would like to know other details like duration of hives, any other allergic diseases, any relation to food or drugs, etc.
At present, if you don't want to use 
calamine lotion, I would suggest you to give her an antihistamine like 
hydroxyzine or 
cetirizine for 3-5 days. You can use both calamine lotion and an antihistamine drug, that will be better.
As they are related to diaper areas, I would suggest you to change diapers more frequently and also change the type of diapers, if possible.
If this does not help, I would suggest you to 
consult a pediatrician, who will ask in detail about her problem and can examine her hives/rashes and can come to some conclusion.
Hope this will be helpful to you.
Wish your daughter the best of the health.
Regards.