There is a phenomena called "Holiday Allergy Season". This is when kids go off to college or their own apts and when they visit mom & dad’s their allergies flair up. Allergy docs actually laugh that they are busiest b/t Thanksgiving & the New Year. I’m being honest about this I’m not making it up.
When I got the hubby, he was pretty allergic to my cats. I got hepa filters, locked the kitties out of the bedroom, and vacuumed regularly. He eventually developed allergy tolerance to the cats. Kitties tend to cause more allergies than other beasts b/c of the factors in their saliva. The hubby has asthma as well so we have to keep stuff tidy & keep him on his meds.
I have MAJOR seasonal allergies and I use the allergy nasal spray. Its very effective, but has not been so effective w/ ragweed this season. I would suggest doing the filter and possible looking into other medications for her. Good Luck!