Have courage to be a woman

I was at a party last night (fast report; nothing special, nice people, fairly fun night) and there was this girl who was very lovely, round my age but with a personal trait I find very problematic. I can't say I am irritated by it as I had the same problem… in high school! But I find it a big problem when a women of 30 (or maybe even more in her case) still dresses and acts like a 14 year old tomboy who tries to hide the fact she is developing breasts.
I know accepting one's sexuality and growing into your femininity isn't an easy task and that it is a lifelong process, but when I see women (/girls) like this (or men who are still boys) I just want to shout: For goodness sake, snap out of it!!! You ARE A WOMEN, not a girl. You have boobs and that's ok, so stop wearing your older brother's T-shirts.
To set the record clear, we all know about my tendency for Nike High Dunk trainers, so I am not advocating all women should dress in Roland Mouret Galaxy dress and wear exclusively 6 inch heals to make a statement of their womanhood. It is more than just clothes. It is the attitude, it is the acceptance of your sex, it is about growing up and not being afraid of who you are.
This is a huge subject and I know I can not begin to cover it plus I don't want to get overly pathetic in "celebrating" femininity. Am just getting it out there and here is a lovely very feminine drawing for every one to enjoy.