Ratatosk - OK...1st, my son did not crawl either...he did exactly what your 9month old son is doing..he started walking when he was 13months old..AND
he was not potty trained till he was 3..BIG Deal..when he was ready he was ready and I tuned everyone out and told them when he's ready he will be ready.......
AS for competing grandma's or your MIL (who yes you are right are morons)
this may help or at least you make get some pleasure out of it..When talking to your MIL..Mention a girlfriend of yours who was complaining to you how much "her MIL" is spoiling her new grandson, how her grandson in her eyes does not wrong, How gilfriend's MIL buys lots of toys, clothes, books, babysits, and just brags about her grandson over and over...Get it?
MAYBE, this will get your MIL to review her actions and comments with your son and you will get some peace...
Your MIL should be happy and proud she has a healthy grandson with two good parents instead of worrying what he is or isn't doing at 9months old!