Someone should definitely tell her that the way she is wearing the shirt is improper. Wouldn't someone correct a Scout who had his shirt on that way? On the Uniform inspection sheet for Female Leaders, the picture shows all 3 women with shirts buttoned up (except of course the very top one). Female Cub Scout leaders can wear either the yellow or tan shirt. Female Boy Scout leaders must wear the tan shirt. Again, this info is taken directly from the uniform inspection sheet.
I was a Webelos Den Leader (my son is in Boy Scouting now, YAY!). I wore the tan shirt and khaki pants, with the WDL scarf, neckerchief, and hat. I'm not exactly a petite woman by any means and needless to say, the uniform did not make me feel comfortable. However, to set a good example, I endured. All Scouting women know that the uniform is not made for us.
Lisabob hit the nail on the head - I felt like a tent wearing the man's shirt. But I wore it proudly - and buttoned up. She should wear the uniform properly or not at all.