She has had 2 kittens bfore but they died this time she had
4 but she only feeds one help

You need to bottle feed the other one, you can get baby kitten powdered milk from a pet store or Walmart, etc. with a small tiny bottle, you may have to start bottle feeding the other one soon, every 2 hours. Or they will die, she is feeding one probably since she only has milk enough for one.