I would check and see if their starting to get teeth if not just let them nurse for a while longer. If they have teeth, start out with soft, wet, can food and go from there.
Mom cats often adopt another cat's litter, especially if the mom recently gave birth. For young kittens, that's okay BUT mom will need more food with protein (e.g. a good dry and wet food). However, 12-week old kittens should NOT be nursing. Separate the older kittens from their "adopted" mom and get them onto dry food.
The mother cat gives birth to the kittens.
milk
At five weeks old, the kittens should start the weaning process. Start introducing canned food to them, or a watered down normal kibble. You can also start teaching them to use the litterbox now!
She felt that her kittens would be safer there.
Well actually kittens don't start to eat solid food until they are 4 weeks old, unless you are talking about them not drinking their milk.
Kittens need their mother's milk for at least 8 weeks.The answer to your question is yes.
Kittens usually begin the weaning process around 4-6 weeks of age. They begin by taking an interest, or picking at their mother's solid food. At this age they will still be suckling and getting nutrients from their mother, but putting a tiny bit of wet food down every few hours will entice them to eat. You could see if they will lick food off your fingertip or off their own paws. This first stage can take several days. Mushed up wet food, or wet food that is throughly mixed with a little water or kitten milk is the best type of food for them right now. It is easy for them to eat and digest. It is advisable not to try dry food as, even softened with water, kittens may still not be able to eat it. As the kittens get older and bigger, you can slowly decrease the amount of water or kitten milk you use in the food, and leave slightly larger chunks for them to chew. Be sure to feed them from a plate and not a bowl, as it is easier for the kittens to pick up the food.
Kittens naturally get goop in their eyes; you just need to keep wiping their tear ducts regularly. If the goop seems exessive, take the kittens to a vet.
Jus like a real life mommy, they are able to produce milk as ling as the kittens are nursing. When the kittens have reached the appropriate age to be weened YOU have to keep a close eye and try to get your kittens to stop nursing....kittens will start eating the food if you put it out- try to get food meant for kittens or even soft food- not canned for- jus a softer version of dry cat food. Once all of your kittens have eaten regular food- DEF make sure none of them are nursing- then momma cats dries up and all is well!
Call the fire department .
It is probably teething. Give it something else to chew on.