Oh come on folks the kids probably just got a cold and everyone rushes to buttume its an allergy. I'm not "anti-allergy" (I've got two myself) but it's way too early to buttume this is the most likely cause. I think after a 7-10 days I'd take your daughter to see the doctor. Have them listen to her chest.
There are several harmless viruses which that can last for months. One of our three year old twins went down with something similar to this last year (eg cough, runny nose, no temperature). Three rounds of Antibiotics only fixed him up for a few days at a time so they gave him a blood test. Turns out he had CMV - This is a virus that at least 50% of people in the USA get before age 40.
Apart from the slight cough and runny nose he was reasonably normal and it didn't seem to slow him down much (although he did fall asleep one or twice in the afternoon). Eventually he recoverd on his own.
Then 8 weeks ago it appeared to come back. More rounds of antibiotics and another blood test and it turns out to be another virus that can last a few months.
Colin
