First of all, the whole dream gives people the feeling of two words-"disorder"; First, the criminal married your wife (bigamy), then he wore an ancient costume (time and space disorder), then his brother-in-law got pregnant (male pregnancy), then you turned your son into a daughter (transsexual), then you gave birth to a child with a stick (against physiological common sense), and finally the child was born with long hair and beard (also against physiological common sense).
So, string these images together and what will you find? I found that these images are related to gender, sexual characteristics and gender relations, and lz's dream is obviously an anxious dream, that is to say, in real life, lz has repressed instinct, or you have something you want to do in your heart, but you didn't do it, so you were depressed, so you had an anxious dream. And this depressing thing is likely to have something to do with both sexes? The characters in the dream are your wife, your brother-in-law and your mother. Finally, the description of the child is: "long hair, long beard, and a little oblique eyes." I believe this also symbolizes a person, or several people ... What is the relationship between these characters, which determines the specific meaning of your dream. I guess this should involve some of your views on these people and some of your gender. Besides, is there any other gender relationship involved?
Because I don't know lz himself and those people related to you, I can't analyze this dream completely, but I want to provide you with such an idea, hoping to help you ~