When you enter into a marriage, not only do you gain a husband -- you gain his family, too. If your husband's sister is a narcissist, getting along with her may seem impossible. Narcissists have an inflated sense of self-worth, show lack of empathy toward others and are preoccupied with themselves. An article in the February 2011 edition of the "Monitor on Psychology" entitled, "Reflecting on Narcissism," shares research that indicates narcissism is on the rise. Since you won't be able to avoid interacting with your sister-in-law, it's important to find the best way to deal with her to keep harmony in the family.
Learn About Her Past
You may have an easier time dealing with your sister-in-law if you understand possible reasons for her narcissistic characteristics. Some experts believe that narcissistic behavior is rooted in childhood experiences, according to Randi Kreger, author of the article, "Shame Is at the Root of Narcissistic, Borderline Personality Disorders," published in Psychology Today. The article explains that some research shows parental deprivation and constant shaming may lead to narcissism. Other researchers believe parents can do too much for their children, causing them to feel entitled and become narcissistic. Ask your husband about his sister's childhood and try to feel empathy toward her.
Set Your Limits
If you find that dealing with your husband's sister always results in your blood pressure rising, you should set some limits. It is not necessary to explain your boundaries to your sister-in-law. For example, if you find helping prepare family meals with her stressful, you might go set the table or offer to clean up afterwards instead. Explain to your husband that you need to limit your interactions with his sister in certain situations to avoid problems.
Avoid Conflict, If Possible
When you find that you and your sister-in-law have a difference of opinion, avoid trying to reason or argue with her. It is best to clearly and briefly state your position and avoid getting into a discussion. If she tries to instigate an argument, you should take the high road and refuse to engage. If your disagreement is about something important, such as treatment of your children, enlist your husband's support and stand your ground.
Provide Support in a Practical Way
You may be able to build your relationship with your husband's sister with practical displays of support. Maybe you can help her with tasks such as cooking or household chores to show your support. To prevent her from stepping in and taking control of your efforts, help her with something that is outside her expertise. Your attempts to be closer to your sister-in-law will show your husband that you value his family.