Private investigator Marilyn Greene has spent her life breaking new ground for women while holding down the fort at home. Without a guide book or role model to show her how, Ms. Greene has raised two teenaged boys while building a successful career finding missing people.By pursuing her lifelong interest, she has confronted and broken through many gender stereotypes. She was blocked from becoming a New York state trooper in the '60s, but a decade later was one of the first women to become a licensed private investigator. Her advice to women? "If someone blocks the front door, go in the back door. You'll still be in the same room." Greene says being one of the few women in her field, she often feels guilty for neglecting her family. "Society subjects women to guilt for the pursuit of what a male considers a right," she says. "Guilt is the most destructive thing to our self-worth. You have to feel free to develop your own interests. "We don't wash clothes on rocks anymore. We still have a lot of free time to do a lot of social good." Greene says she is encouraged by the progress of women today. "When I was 19, I couldn't have credit in my own name," she notes. Greene has also found that being a woman private investigator can be an advantage. She says neither men, women, nor children are intimidated by her. "And rarely does anyone refuse to talk to me. It's impolite to refuse to speak to a woman."