threat of jail

My son just separated from his cruel wife. For years, she has treated him as an inferior and hardly attented to his needs even during meals in his in-law's house. Unfortunately, to make the separation final, he said he had been dating another woman... and this was concurred by a supposed officemate's "sympathetic" text messages to the wife. The dating has actually stopped a long time ago. But now the wife is threatening to file a lawsuit against my son and have him jailed, even if there's no actual evidence. Can she do this? Will my son be jailed as soon as the case is filed or will there be a trial of some sort?
Thank you

your son will always have the right to be heard and he will not be automatically be jailed. if it was really just dating, then he has no criminal liability