@BWAggieBride: Thank you for providing the additional information.
This is a sensitive issue for many reasons. I would encourage you not to demote your cousin, because, ultimately, your relationship with all of these ladies — especially the cousin who has been like a sister to you — should be far more important to you than whatever role these ladies are playing in your wedding.
I also had eight bridesmaids, including two matrons of honor (and two junior bridesmaids.) Three of my attendants were DH’s daughters and DIL, and one was my SIL (my brother’s wife.) I have many friends with whom I am close whom I could have asked to be bridesmaids, but, ultimately, family is extremely important. Many friendships will wax and wane thoughout the seasons of your life, but family will always be family.
One of my two matrons of honor (she also was the one in the #1 position in my wedding) has been like a sister to me for decades. She lives very far away in another state. She was not at all in the financial position to attend or contribute toward a shower for me. I didn’t care at all. I honestly was so thankful and thrilled that she and her husband and some of their children were able to travel hundreds of miles even to attend and participate in my wedding.
I had another friend who was a bridesmaid. She and my other Maid/Matron of Honor were the only two adult bridesmaids who were local to me. She and my local Maid/Matron of Honor were the ones who were able to go dress shopping with me and who so generously offered to host and fund my shower. (My SIL also helped from afar, since she also was out-of-state and couldn’t travel.)
If these relationships are important to you, I would encourage you not to view the worth or worthiness of your bridal attendants in terms of the time and financial investments that they are able to make in your pre-wedding events and processes. Although it’s wonderful when some of your bridesmaids offer to help with wedding details or to host a shower for you, these gestures should be viewed as much-appreciated “extra” benefits, not as requirements or even expectations.
I’m sure that your hard-working and helpful local bridesmaid understands completely why you would have chosen your cousin to stand closest to you that day and that she is not at all expecting you to throw your Maid/Matron of Honor overboard based on her not being able to take on the lion’s share — or even any — of the work of preparing for your wedding.
Being asked to serve as a maid or matron of honor or a bridesmaid in a friend or family member’s wedding truly should be an honor in and of itself. That honor should not also come with a list of requirements — other than being willing to purchase and wear the brides’s choice of dress and perhaps to wear a specific color or type of shoes and jewelry and to be present for the rehearsal and the wedding — to maintain this position of honor.
Those are my thoughts. I hope some of them are helpful.