My mother used to sing a version of Bob Clayton's first post above, with verses that sounded more like a parody. All I remember is:
Sister Lucy wore a low-necked dress (low necked dress)
Sister Lucy wore a low-necked dress (low necked dress)
Sister Lucy wore a low-necked dress
It was too low, I must confess
There's no hiding place down there!

I know there were more verses. Wonder if she remembers them?