One of the mums from DS's school does not like me and makes it obvious but I have no idea why. When the boys started school she invited DS and I round for a playdate and all was fine. I sent her a text a few weeks later inviting them to ours and she read it but did not reply and since then has made it very obvious that she doesn't like me. She mostly ignores me if I say hello to her or just rolls her eyes, yet is lovely and friendly with everyone else, who all think she is great!
It is difficult as the boys are friends at school and there are lots of parties and school events where we come into contact with each other, not to mention school collection each day (the boys are in the same class and we have to wait in a small space to collect from their classroom!)
I know as adults we are not meant to care if someone likes us or not but I do find it quite upsetting and it makes me uncomfortable :(