bubbly eyes

chickens can be very cruel and will attack an ill chicken. They have been known to attack and kill the poorly bird.
Use cooled boiled water to cleanse her eyes.

you cant, just keep a close eye on them for the next few weeks (it can take a couple of weeks for the symptoms to show).
Some people will cull the infected bird rather than treating especially if they are breeders and have show birds as they don't want to take the risk of infecting the others and also because they cant use them for breeding (they may not be able to tell her eggs from another birds) but if they are pets then others will get treatment.

it is a term which means to kill livestock 

mum will not take her so well thats that one eye is fine but the other is shut and will not open.i hope she will recover without needing to go to the vet