I'll try and keep this short and to the point. While I realize it's a pretty small issue, it has been causing some stress and I'm honestly not sure what is the right thing to do.
DF and I are having a semi-destination (our families are spread out all over the world so we picked a central-ish location) wedding. It will be a very small wedding with only very close family attending. DF and I and both of our parents will all be arriving two days prior to the wedding.
The wedding coordinator has asked that we drop by the ceremony site the day before the wedding to take a look around, make any last-minute changes, etc. DF is extremely laid-back with wedding plans and the guys had already made some plans for golf, so I decided I'd go with my mom.
I've been in communication with both sides of our family trying to coordinate our plans for the day before the wedding (a family brunch, DF has some activities planned with the guys, etc.). When I mentioned my mom and I going to visit the ceremony venue the day before, my future SIL and MIL asked if they could come with us. I said sure, not thinking anything of it.
When I mentioned to my mom that they would be joining us, my mom was upset as she had expected it would be just the two of us and was looking forward to it as our only "mother daughter" activity throughout the trip. She noted that she is helping us out significantly with the costs of the wedding and has been involved in some of the planning, while future MIL is not (but she does live across the world!). She seemed so disappointed that it would now be us and the in-laws and asked if I would feel comfortable asking them if we could keep it just the two of us.
To be honest, I don't feel comfortable preventing them from joining us and ultimately want to have as great a relationship with them as possible. Future MIL and SIL are lovely and I have no issues with them joining us at all. But my mom has been bringing this up fairly regularly wondering if I've talked to them yet and persisting that she is hoping for this to be a mother-daughter activity as we've been doing the rest of the planning together. She is clearly upset.
I just want everyone happy! Any thoughts on the best way to handle this?