I have the most easy going mother in the world. Seriously-anything goes with her, she's not opinionated in the least, and always has been incredibly supportive. When it came to my wedding, I assumed I wouldn't have any mom-issues since she's so easy-breezy and thinks everything I do is great. I do know she doesn't like to have a lot to do and she can get easily overwhelmed-so I carefully planned my wedding without putting any stress on her, and made sure she had nothing to do when the big day came except for wake up and show up. Imagine my surprise when she was a big ball of stress and anxious nerves on my wedding day. I didn't know what to do with her! I had never seen her in such a state, and I had to keep coaching her to calm down and just relax. It was so unexpected.
After my wedding my new husband and I were trying to process what the heck happened to my cool as ice mom on my wedding day. We thought we were doing her a favor by not giving her anything to do, but in hindsight I think she would have relaxed a bit if she had one thing to be responsible for. It would have kept her mind preoccupied and she would have felt useful, rather than walking around aimlessly all morning filled with worry.
I have talked to so many brides who have problems planning their weddings because of overly opinionated moms and mother-in-laws, everyone's feelings getting hurt, and tensions rising. Sometimes it even leads to arguing with fiancees on how to incorporate moms into weddings, yet still doing what you want to do as a couple, and remaining respectful. It's a hard balance.
My advice is this: pick a job for your mom and your mother-in-law that they will care about and can contribute to your wedding in a way that is meaningful for them and helpful for you. You may have to get really creative with this-but I think that our moms just want us to be happy (in most cases) and they are unsure of how to process this transition of our life. Mother-in-laws are often even trickier because they are trying to figure out how much to offer their help but not be overbearing. Unfortunately, a lot of these emotions turn into arguments about petty things that don't matter that much in the grand scheme of your wedding.
Another idea came from a bride who knew her mom would be stressed on her wedding day, so she assigned a "personal attendant" to her mom! It was her mom's best friend, and she knew her job was to keep her friend calm, cool, and collected the whole day. I thought this was a genius idea! Sometimes our moms just need a little TLC.
I encourage you to brainstorm with your fiancee about how to proactively include your moms in your wedding before things get crazy, and hopefully you will find a little less stress as you go through your engagement season.