Here's my confession: I can't whistle. Not a lick. Not a note. Nothing. I've tried to learn lots over the years. Many have tried to teach me. But, my tongue and lips do not want to cooperate. I'm totally okay with it.
Here's the kicker: Kian can whistle. Already. Not a song, of course. But he's recently perfected his "uh OH" and lip rounding. He liked rounded lips. Then he discovered when blowing air in and out while making that "oh" face, it makes a pretty cool noise. So, he goes around the house, throughout the day "whistling".