Cats have the pineal gland which is responsible for hormone melatonin production. Leaving light for a cat at night might cause issues with the melatonin production and disrupt the cat’s sleep. So, cats don't really need light at night.
First you should create a safe space to leave your kitten alone. Always leave a water bowl and a food bowl, as well as a litter box for your cat. Also, ensure your kitten will not hurt herself while you are away.