When you are in a serious relationship or married, your partner's family becomes your family - even if you don't get along. Chances are there are going to be some people you do like, after all, the person you love came from this family. But there might also be people you don't like and don't want to be around. Unfortunately, if you don't want to cause a big problem in your relationship, you are going to need to find a way to tolerate everyone, even those that you simply can't stand.
The following tips can help:
You need to be congenial but you don't have to be best friends. Think about where you work. There are probably people you enjoy spending time with, those that you are friendly with but only during work hours, those you associate with only when necessary, and those that you avoid whenever possible. Even so, you have learned how to get along to protect your job. Your in-laws are the same. You don't need to become best friends, or even overly friendly with everyone, but you should be congenial. For some in-laws, remaining cordial is the best you can hope for in the beginning, but as time goes on, acceptance can lead to a better relationship.
Find common ground. This might be hard with some in-laws, but search for a common interest or neutral conversation to get started. Stay away from topics you know are controversial or will create a defensive reaction (in you or the other person). Have some neutral topics ready so if the conversation starts to go downhill, you can quickly change the subject and get back on neutral ground.
Don't try to solve problems at a family gathering. If you have a disagreement or ongoing feud with one particular relative, don't try to have a conversation to clear the air in the middle of a holiday celebration or family gathering. Instead, be cordial and suggest you sit down together at a later time to talk through your differences. If sitting down together is impossible or you believe you won't be able to hold your temper, consider email, which provides
distance and gives you time to think about a response before quickly saying something you will regret later.
When you feel attacked, don't respond with more negativity. If you are consistently attacked by family members because they don't like you, be prepared with a non-confrontational answer. Suppose you are criticized because you don't have a college degree. When confronted, answer with something like, "Thank you for your concern, I will certainly take that into consideration." Then move along to talk with someone else. It is difficult for a person to complain about you because you were courteous.
Avoid complaining about your in-laws to your partner. This is her family and while she might agree with some of your assessments she is probably more accepting of everyone's faults because she also knows their strengths. Unless you are sure your partner feels the same way about a particular person, keep your negative comments to a minimum. Asking for suggestions on how to best deal with this person will probably work better than complaining.
Pay attention to your reactions. Your dislike of the relative might put you on edge, causing you to react defensively immediately. Take a deep breath, act rationally and reasonably, and don't give the in-law any reason to talk about you to others.