Normally, the kitten weaning process begins at about four weeks of age. “With mom, they’ll start to try to eat her food, and she’ll push them away from her,” says Benson. But if you’re weaning a kitten that has been orphaned, you can start a little earlier, between three and four weeks.ormally, the kitten weaning process begins at about four weeks of age. “With mom, they’ll start to try to eat her food, and she’ll push them away from her,” says Benson. But if you’re weaning a kitten that has been orphaned, you can start a little earlier, between three and four weeks.