She'll have a good chance if she makes it through the night, although they are so fragile that they often die of shock.
At the very least she needs a warm, dark place. A small aquarium or shoebox will work; cover the bottom with a towel and some paper towel. Wrap a heating pad around one side, or place a hot water bottle on one side.
Hummingbirds also have really fast metabolisms, which means she's going to need sustenance soon. You'll need a very, very small syringe. She's probably in shock and might not eat, but you can try.
Here is how to make hummingbird nectar (it's not perfect, but will do in a pinch):
Mix 4 parts water to 1 part table sugar in a pan. For example, use 1 cup sugar to 4 cups water. Do not use honey, Jell-O or brown sugar. Especially do not use artificial sweeteners. Putting hummingbirds on a diet will kill them. They burn prodigious amounts of energy for their size and need real sugar. Do not use red food coloring. It is unnecessary and can harm the little hummers even in low concentrations because they eat so much nectar. If your feeder isn't red, tie a red ribbon on it as described in the Feeders section, above. Do not add anything else that you might think of. Just sugar and water, that's all.
Bring to a boil then remove from the heat. Stir it while it is heating until all of the sugar is dissolved. Don't boil it for long because that will change the ratio as water is boiled off. The reason for boiling is not to make syrup, but to drive out the chlorine in the water and to kill mold and yeast spores that might be in the sugar. This will help make the nectar last longer both in the feeder and in your refrigerator.
Cover and allow to cool before using or pouring into the storage bottle.
