I don't usually post here but you folks are usually solid on the advice.
I am cohosting a baby shower for my best friend with her mother and MIL. MIL owns a small toy store and was insisting that I include a list of local retailers on the invite that she networks with, in spite of the fact that BFF and her H declined registries at those stores and are registered elsewhere. They decided to register at one children's clothing store to appease her. Today, I showed her a draft of the invite with both registries and she responded that I had forgotten to include her store. I said that I didn't realize that they had a registry through her store and she said that they don't yet but to include it and she would make them do it.
I hardcore side-eye the idea of her making money off of her grandchild AND a shower that she is co-hosting and feel like this is a major etiquette breach. I know that BFF and H don't want to register there and have told her as much. How do I politely tell her that this is not okay?