There are a couple other things that are supposed to really help with allergies but I have never done either consistently enough to vouch for them one way or the other. One is eating local honey. I do buy local honey and use it but I read that you should take a couple teaspoons a day to receive the allergy benefits. I have a hard time taking it straight but have been mixing it into my green tea.
The other natural allergy reliever is Quercitin. I found some great info at the following link:
http://www.immunesupport.com/92fal004.htm. According to this site, taking 1000 to 2000 mg per day will help with allergy and asthma symptoms (I suffer from both). It also suggests taking Bromelain with it to improve the absorb-ability of the Quercitin. My mom swears by quercitin (which can be obtained through onions and apples as well) but again, I've never been consistent enough with it to know whether it would work for us.
Both Hibiscus and Nettle are great antihistamines and since they can be taken in tea form, would be easy to administer to kids.
I usually order my herbs from either Iherb.com or Vitacost.com and for this I found Iherb to have the better pricing if you buy the Now Foods brand. I may have to place an order and give this one a try as well. I purchased my Hyland's pills through Frontier and they had the absolute best price but if you don't have a way of ordering through them wholesale, then I suggest Iherb for the next best price.
So, I hope this helps. I'm gonna go help myself to a teaspoon of honey and let the experiment begin!