perpetuallysad, you are not a nut case. I know I sound like a broken record but negative chatter and self-deprecation are so unhelpful.

Arguing fairly is a worthy goal: http://www.ehow.com/how_5826775_argu...lligently.html

Instead of you did this, or you said that, what seems to work a bit better is to talk about how you feel when your sister does certain things.

"Sister, I care about the nieces and nephews very much. Would it be possible for me and my child to visit with nephew to wish him a happy birthday and maybe take him out to lunch?

I understand you have every right to invite whomever you want to nephew's party. You know I do not see eye to eye with mom. I would appreciate a call to let me know when you invite Mom so alternative arrangements may be made ... (to do whatever).

I know that you do not agree with how I feel about Mom. That is your right. But it makes me feel sad that you do not have respect for my feelings. I believe I have legitimate reasons for feeling the way I do and I would appreciate it if you give me the same respect you give mom."

Now, if your sister is unwilling to go along with the program, you will have a difficult choice to make. Either you accept what your sister decides is appropriate for you, or you set your own boundaries and be assertive in a non-aggressive way.

What makes this situation more difficult is the history of the relationships of the parties. Each of you have come to expect the others to act in familiar ways. It make take some time for a different approach from you to sink in.

By the way, I do not mean to be condescending or officious. Please tell me to fly a kite in your new boundary-setting, assertive style.

Have a great day.