If you don’t show good manners, you run the risk of ruining your reputation.
This can prevent you from being promoted and in some cases may even get you fired.
The foundation of proper etiquette is behavior that is accepted as gracious and polite in social, professional, and family situations.
Good manners can mean the difference between success and failure in many aspects of life.
Remember if you do decide to attend that you may have a different role than you would, had you still been the daughter or son-in-law.