Am so sorry to hear of your daughter's allergy. We currently have five cats we consider our "children" (we used to have nine...all of them indoor (and for those who wonder about nine indoor cats, let me quickly add that my wife is such a fanatic that even when we had nine, if you entered our home you wouldn't know we even one unless you saw them)) so both of us commisserate with her.
But tell your daughter certainly all is not lost. I remember reading some years ago that people were astounded to learn that the individual responsible for nutrition for a huge number of resident cats at a pet food company was extremely allergic to cats. When asked how he could work around so many felines, he replied that he absolutely loved his job and especially all of his charges. He just took medication to alleviate the symptoms.
What you advised your daughter is absolutely one of the best things to do to keep the allergens under control. As the President of our local Humane Society, I some time back confirmed that with our Vet.