I discovered the smart thing. When my daughter wears something I consider too low-cut, I remark “Hey, you have boobs.”. Then I stare at them. She gets the message.
There is NOTHING creepier than your dad noticing your boobs.
Wow, great tactic! Mine’s 12 going on 22 and has been eschewed by her “friends” for wearing “old lady panties” instead of thongs. 12 year olds, thongs?