Is the mother entitled to refuse to sell a farm registered in her name, which the father had intended to give to their children, and now wants to sell, knowing that it cannot be sold without her consent, and he has threatened to divorce her after the sale to marry another woman?

The marital life is built on trust and affection. If the farm belongs to your father and he did not gift it to your mother, then she has no right to prevent him from disposing of it under the pretext that it was registered in her name for special circumstances, or to prevent him from disposing of his money under the pretext of his divorce from her. Mere registration does not make it her property. The father should observe his wife's rights and preserve her affection. He should not abandon her due to a dispute that can be overcome. He may marry another while keeping her as his wife.