Someone pointed out a handy, easy to use guide these people can keep in mind . . . or write on an index card and tuck behind their phones in that over-sized case . . .
if the toy is designed to teach nurturing or development of life . . . it's for a girl
if the toy is designed to leave the child with a god-like control over life and death or cause destruction . . . it's for a boy.
Which is so messed up, you should probably go have a bit of a lie-down.