Funny you should post this today, I just had to call my pharmacist to find out if I could take my allergy pills I have in the house and I'm on topamax and depakote (new this past month). There were no reactions listed between them and Reactine which has cetirizine as the active ingredient in it. I have a generic one that has cetirizine and hydroxyzine and it is safe.
p.s. she may want to try a neti pot or a sinus rinse to help with her ears, the sinus rinse helps me with my allergies and it's drug free!