My daughter has been having a blocked nose and sneezing. it is not flu. i think she is starting with allergies /sinuses. she is five, what is my next step???

Avoid the allergen.: I know it is easier said than done, however the best thing would be to avoid what she may be allergic to. There are options of taking medications that reduce the symptoms of allergies and talking to you pharmacist may help in selecting the best option for your daughter and they would be able to tell you how to use it as well.