Oh YES!!! I can SO sympathise. My mil drives me nuts with her continual diagnosing of what's up with DS - always directed at him, not me, since she can't be direct but I know it's her way of telling me what she thinks I should do with him. E.g:
DS makes tiny fuss (cos he's bored with his toy or sick of grandma being in his face ALL the time) and instantly its 'Oh nononononono shhshshsh!' (cos babies aren't allowed to be anything except asleep or continually happy (heavy sarcasm), followed by 'you're getting hungry aren't you?' or 'oh you're tired aren't you little man' or 'is some wind bothering you?'. And she'll say these things even after I've pointed out that he's only recently just got up from a good nap and has just eaten and given great big burps.
She just can't let him just be. It's a CONTINUAL diagnosis of his state of being and what's right/wrong with him - HELLO! I spend 24/7 with him for the past 7.5months, I think I know what's wrong with him! Stop telling me!! (of course I just scream this loudly inside my own head)
I think she has struggled with the idea of him being on a routine and not put on the boob every time he fussed or into bed the moment he made a tiny squeak - think she must have thought I was being awfully cruel. But thankfully through seeing that he's actually a very mellow and happy little guy who naps/sleeps great and has his needs met as a result of his routine, I think she has had to agree that it does work. But that doesn't stop her from trying to guess all the time!!

When I was pregnant I did get warned by many parents that the unsolicited advice I was getting about pregnancy was nothing compared to the quantity of it once the baby actually arrives, and also how much more irritating it is to try and tollerate! Boy they were right!!!