If you have previously recommended this thread, you should see a tick / check mark on the recommend button. Click the tick to undo the recommendation (the tick may appear to change to a cross as you do this.) If you added a comment with your recommendation, you will need to delete that from your facebook wall separately.
I'm a French mum too and I live in Bath. My DD is 15 months old so a bit younger than your little boy but I was thinking of putting something on the notice board in the library to see if there were any other french mummies who may want to meet up so that the little ones could play with other French speaking children? Let me know if you are interested.