Don't be offended. It happens. I have never been in a wedding before -- but I betta before I die. This is a stressful time for your cousin. I am not sure how she picked her wedding party, but I know for me (single girl here just projecting her wedding dreams), it would be hard to include all of my significant folks in my wedding party. I would want my cousins but at the same time, like you and your cousin, we have grown apart and recognizing that -- I would not have them in my wedding party but would explain to them that their presence @ my wedding is crucial to me.
If it helps, depending on your comfort level, present it to your cousin with a casual attitude as well as loving. Were you offended @ not being asked way back when she first determined her wedding party? If not -- then say nothing.
Did I give too many options? I am supposed to be sleep but I felt you needing my presence.
__________________ I am a woman, I make mistakes. I make them often. God has given me a talent and that's it. ~ Jill Scott