Dog allergy

Looking for some advice.  The details here are a bit long, so please hang with me.  We currently have a 6 year old Golden Retriever, a 4 year old daughter and a 16 month old daughter.  After deciding to get a puppy (also Golden) we visited a breeder to see the litter.  During the 2nd and 3rd visit, our 4 year old started having an allergic reaction, sneezing and itchy eyes.
This of course has us concerned.  She does not react at all to our dog at home.  Additional points:

-The puppies were together with 3 adult Goldens, there is at least one cat in the house (daughter IS allergic to cats).
-During the 3rd visit the puppies were moved into a garage kennel.  Not sure how much the cat may or may not be around them.
-The conditions weren't pristine, newspapers and a carpet square.

So the questions are...could she be allergic to one Golden and not another?  Could it be the concentration of so many dogs all together?  If tested for allergies, is there anyway to make a good decision since she doesn't react to our current dog?  Could it be from the cat roaming around?  Could it be a general animal allergy caused by the conditions (it's kind of like a barn/farm home).  They have chickens, goats, lot of dogs, a cat, etc.  Could it be because the dog is a puppy?  Is there anyway to test her allergy to a specific dog (ie, the puppy we might take)?


To anyone that read through that long post and offers advice, Thank you!