definitely sounds like allergies. have you been tested? get tested before you keep taking meds (well, at least after this particular episode is done because you need to be off allergy meds for about 10 days before you can get tested).
anyways, get off milk products --milk makes you produce more phlem. I don't think zyrtec has a decongestant. so what the doctor gave your daughter probably had a decongestant and that helped to dry her runny nose.
question everything... from xmas tree to flowers, plants in the house, plants outside the house, air freshener, shampoo, lotions, cleaner, etc.
the netti pot is a great suggestion. also, try and use chemical-free cleaners.
get tested for allergies so you know what to avoid. just taking allergy meds is not the answer. After I stopped eating lettuce, sunflower seeds/oil and safflower oil I only have to take allergy meds/decongestant every few weeks sometimes months go by and I don't need it. you see, I'm allergic to ragweeds and in that family you'll find lettuce, artichokes, sunflower, safflower, daisies (my favorite flowers), dandelions, echinacea, chamomile, etc. now that companies are trying to get away from soy oil... they're using sunflower and safflower oil for everything. That's making it very difficult for me to enjoy snacks and many other prepared food products. I'm not saying that's your problem, but just wanted to show that avoiding a few things can have a big impact in your everyday life. Good luck! and get yourself and your daughter tested. ~C.~