I would not de-worm her with anything over the counter. Cats especially can be really sensitive to stuff like that especially when they are small. I would consult a vet before you worm her since she is sick and so young. If the eye boogers are green or she stops eating then she needs to go back on antibiotics. Ask your vet if he thinks she has feline herpies. If he thinks she does then ask about giving her lysine which helps boost their immune against the herpies.
Keep her eyes clean with the cotton balls and water like Kait18 said. Take her in the bathroom when with you when you take a hot shower. The steam will help her breath better. The humidifier is also a good idea. You can even put a little Vicks in the water.