That Brennan Girl(1946)

Raised by Natalie Brennan, a flamboyant and irresponsible mother, Ziggy Brennan gets involved in hustling men at a young age. She hangs around with a wild crowd and learns gets her "street smarts" first from her mother, who wants everyone to think they are sisters, and then from Denny Reagan, an older man. He starts teaching her his tricks of the trade and she falls right in line with his crooked ways. Then one night she meets Martin J. 'Mart' Neilson, a tall, handsome, honest farmer boy who's a sailor and they fall in love. While he's away fighting the war, she discovers she's pregnant.