Pixieonthemoor 
Mil told me that babies need to cry, as it is good for their lungs. She then added the caveat, 'but not baby boys - it is bad for them.'
I know the 'good for their lungs' crap is often peddled, but the boy thing was a new one on me. I erred on the side of caution and left neither child to cry. 
She also told me my 'womb would be stronger' after a miscarriage. In that instance, I think she was just trying to find something nice to say, during what was an awful time for us all, her included. Having had four miscarriages and two living children, by her reckoning my womb must now be in with a chance for Rio 2016.
Her other gem was, on seeing 4yo dd get upset by the noise of the sea on a beach holiday, 'You'll have to toughen her up before school!' Dh and I decided that, as her primary school was not on a beach, we probably didn't have to worry.
Mil is very sweet, really. She just occasionally has advice that will apparently burn her up if she doesn't share it. I aspire to be the same, in my dotage. Perhaps I will save this thread for future reference.