It is a pamphlet developed by Modess Sanitary Napkins in 1953; a handy little guide for all those tough questions every girl has about puberty but is too embarrassed to ask her mother.
That's right, "Phooey". The pamphlet goes into the social aspects of growing up, the biology of menstruation, and some helpful advice on how to cope with the changes in your body. Here are my favorite pages:
I have the whole book scanned to a pdf document. If you are interested in reading more of it, please let me know and I'll e-mail it to you. It was clearly written by Modess because of the advertising in it, but there are no copyrights printed in it, so I assume it's ok to reproduce for academic purposes.