In TV and movies (and presumably real life), people will often start advice to boys by saying "hey son..." But I've never once heard any advice to girls start with "hey daughter..." In fact, usually the usage of "daughter" is in some indirect phrase ("that's my daughter" or similar).
Why is "hey daughter" not used? And why does it sound so weird to use it this way when they should be equivalent?
I only see "Hey, son" used in old movies and old TV. This is usually an older man to a younger man, black or white, unlikely to be his son asking or telling some casual information in an instant confidential relationship. If this were done in the late 60s or 70s there would be a confrontation about whose son is whose. Harry Morgan is the last to use this frequently and MASH is set in the 50s.
If an older man were to ask a young lady it would be "Excuse me, miss?"