How Lovely to be a Woman - Bye Bye Birdie. (for an all girls number)
And I agree: nothing immature about When I Grow Up. I had a group of seniors sing it at our thespian night caberet (their final gig) and there wasn't a dry eye in the house.
If we're not having fun, then why are we doing it?
These are DISCUSSION boards, not mutual admiration boards. Discussion only occurs when we are willing to hear what others are thinking, regardless of whether it is alignment to our own thoughts.