Your English is very good and I can understand you easily.

Focus on fluids first, foods second, even though she is very thin. When cats are dehydrated, they won't want to eat, so fluids are the number one priority. While egg is high in protein, she's not really ready for something so heavy right now. Can you get some jars of baby food? Or some chicken soup? Thin the baby food with boiled water until you can draw it up into a syringe and try then very, very slowly in the corner of her mouth. Expect a lot of it to come out of her mouth but she will get some of it. If you have to use chicken soup, you will need to put it through a blender or mash it through a sieve first.

Edited to add - Do Not Give Aspirin to the kitten. It won't help and it will harm her. Vitamins C won't help either. If you want to boost the protein and fats she is getting, use baby food.

Is there anywhere where you can get specialized food for your cat? If there is, they will also have vitamin supplements specially made for cats.