Long time lurker, first time poster.
My nine year old DD started middle school in September. 90% of kids walk to and from the school (about half an hour each way from our house,) all fine with that.
DD was keen to walk with her BFF who lives in the next road, so can call for her on the way. Fab! Then over the summer a lot of their friends mums started asking if their DDs could walk with them too, until one actually started a WhatsApp walking group and there ended up being 9 or 10 of them that all wanted to walk together.
We felt at the time that this was too many, but felt obligated to say ok.
Some of these girls go to after school clubs etc, and it became so complicated we ended up printing out a rota for the girls so they knew who was walking on what day!! Then some would go off without them, some would fall out, etc etc until it just got ridiculous and my DD felt very stressed out by it all.
After one particular incident I felt enough was enough, so I put a message out to the mums saying that I felt they needed a break from each other and that DD and her BFF would just walk together for the time being as it was becoming too stressful. Well you can probably imagine the upheaval that caused 
I have had numerous messages over the past few weeks from various parents about how the girls are now ignoring each other on the way to school, so and so is upset because she thought they were all friends and why don't they want to walk with her any more, etc etc and I've literally had enough. I've tried to be as diplomatic as I can with each of them but it's driving me and DD mad! All she wants to do is have a peaceful walk to school with her best friend!
AIBU about this? I don't want to fall out with any of the mums as we are all close friends. But how can I possibly resolve this?