Quoting Rd.:" I think if you read too much into it, there could be a lot to be said. However that's not my style, ... [snip!] ... when she's overreacting so I guess it's the same thing. I would not like DD saying that to anyone, not at this age anyways."
Someone said it to my son and it irritated me.
I think the underlying message there is a sexist one, and I don't want my son thinking that crying is a sign of weakness, and girls cry more so they are weaker.
"Cry like a baby" is more my style, and that only gets used over petty things he is working up crocodile tears for.