What is the best way to make living amends instead of contacing an ex?

I met my ex in the program, and I am still bitter that things didn't work out between us. I certainly played a role in that, but I think she did, too.

She and I actually had less sex after we moved in together than before.

And, when I asked her how she felt about a woman making more money than her male partner (I always made more than her, but fortunes can change on a dime), she said that she didn't like that. That response bothered me.

Finally, she didn't like to travel like I did.

Anyway, time has passed. Her birthday is coming up, and I found out that she is moving out of town. I was thinking of send her a handwritten note or card wishing her a happy birthday, good luck, and possibly make amends. My sponsor thinks it's a horrible idea.

What do people suggest as living amends, as an alternative for those who have been in a similar situation?

Thanks.