Does Starlight usually spend time outside, or did she 'escape' and spend a few days outside, not being familiar with this experience?
It's very possible that she was either hit by a vehicle, got into a fight with another cat or 'critter' and may have internal injuries, if you see no cuts or bruises, outwardly.
Check the color of her gums; they should be light pink. If they are paler and almost white, she could be bleeding internally and this is truly an emergency.
Try to search for an ER vet in your area from this list; just plug in your zipcode:
Since you'll have to wait for her to see a vet first thing in the morning, if no vets or ER vets are available in your area, for the moment, I would suggest first putting 1/4 tsp. of honey, karo syrup or pancake syrup into her mouth or rub into her gums, as she's most likely hypoglycemic (low blood sugar) from not eating. This might perk her up and spark her appetite. Offer her bland foods like plain boiled chicken breast (skinless), moistened with a little water or tuna water. If she won't drink on her own, dropper feed her water mixed 50/50 with children's unflavored Pedialyte, from the side of her mouth, very gradually. Wait for a swallow after each little bit. You can rub her throat to encourage the swallow reflex. You can also offer some plain jarred baby food chicken containing NO onion or garlic products. Beechnut Stage 1 chicken is a good one.
There's no doubt she needs to be evaluated in person, diagnosed and treated. She may need subcutaneous or IV fluids from the vet.
I hope all will be well with your Starlight! (I just wanted to share that that was the name of my very first cat, many moons ago!)
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