P.M.
As a person suffering from multiple allergies AND severe chemical sensitivities, I doubt that a 24-hour exposure to one of the less-toxic kinds of paint is terribly likely to have caused your daughter's allergies – with the possible exception of peanuts, because latex and peanut allergies are frequently linked.
However, even though that one exposure probably didn't make her sick, many such sensitivity problems are believed to be cumulative. And modern homes are loaded with toxic chemicals, many of which don't have to be revealed by manufacturers.
If you use fabric softeners, air "fresheners," just about any scented or spray-on cleaner, many everyday toiletries, many construction glues or new carpet, if you unwrap plastic packaging indoors, wear fabrics that are set with formadehyde-laced sizing, or use a whole host of other ubiquitous products that are part of modern life, if you drive your children during rush-hour traffic or live near heavily-traveled roads, you have probably exposed yourself and your children in a month to a whole host of toxins with a far more potent total load than that one night of paint fumes. For those of us who have exceeded our maximum tolerable threshhold, breathing the air in many homes and public buildings has become hazardous.
I have to differ with those who argue that "because my child was exposed to X and turned out fine, then X is not harmful." This is simply not sound science. A thousand people could be exposed to a whole year of some toxic X, and only a few of the less robust will succumb to illness per year (again, many sensitivities are cumulative over time). But for those few, the impact can be life-changing.
Very fair children often are more fragile and at risk of allergy and other sensitivities. I used to participate in group testing for sensitivities, and 8 or 9 out of 10 people in the room were extremely fair-skinned and light-haired (I'm a freckled redhead). But nobody's immune. And many of the modern toxins are known to be synergystic – more injurious in combination with others. So "safe" levels of several separate chemicals may be considerably more hazardous when they are inhaled or ingested along with each other. There's just so much researchers have not yet had time to test.
So, D., what to do with all this risk? I have to agree with Lillian that there is really no point whatsoever hanging onto guilt, because there is really no likelihood that you'll every know how large a contribution those paint fumes made. Or any other toxins you may be unknowingly using every day.
The best you can do is learn along the way, make sensible adjustments, and move forward. If you can't accept that life is a risk – for everybody, every day, in ways we can hardly imagine until an accident occurs or an illness strikes, you will be emotionally crippled. Don't do that to yourself, or your family.
Living. Is. Risk. You can't protect your children from everything. And parents who try often limit their kids' ability to lead a challenging, interesting, varied and exciting life. Your daughter's life is already challenged, and perhaps will be limited as a result. But focus on what is still available to her, and don't look back. Teach her how to live as fully as possible within her borders. I am extremely constrained in where I can go physically without suffering severe symptoms, and even when I do attempt an outing during less-crowded times, I am frequently chased out of restaurants, movies, or public restrooms by perfume and other toxins in the air. But I accept my challenges and limitations, and can honestly say that I am a happy person, and my life feels fascinating and worthwhile.
If you want some real information that you can use to clean up your home and remove unnecessary risks, google terms like "non-toxic homes." You'll learn a lot, and can probably significantly decrease the toxic load your kids will have to bear as they grow up.
Peace and blessings.