Very sick stray kitten- help

We recently found a stray kitten, about 4-5 months old. She has been very shy and kept to one room of the house for now. She has gotten very lethargic and refuses to eat or drink. I have been syringing Pedialite all night and day today and think she is feeling a little bit better. My kids and I are also very sick so this has been challenging. I sent my husband to the store for some babyfood chicken but he came home with Chicken Noodle Dinner Can I water down some Wellness Core (fish) to feed to her?
I have done the syrup on the gums too, she is just so sad looking.

FYI: this is the second litter mate we have found, the other one a week earlier. They are identical white kittens. The other one was taken by a local rescue and spayed, tested, vaccinated and already re-homed. This one just showed up huddled on my door.

Thank you in advance!

Yes! That will work fine. Anything at this time is better than nothing.

Can you get her to a vet? There may be other things going on.

You have a good heart to take her in while you are feeling so sick. I hope everyone and the kitty gets better fast.