The original Jeans were by Levi Strauss and were exclusively designed for men. It wasn't until the advent of war, and the call for women to take on the roles of men at the front that jeans (or even trousers) were considered appropriate wear for women.
The role of jeans in the rise of Feminism
Incredible 1970s Vintage Kmart Women's Western Style Blue Denim
511™ Slim Fit Selvedge Men's Jeans - Medium Wash
Corfu denim jeans womens - Gem
Vintage Corfu Blue 'stretchies' 90's Mom Jeans Size 18
Corfu Stretch Denim Jeans Womens Size 8 Blue Zip Close Pockets
The Denim Decade - New Zealand Fashion Museum
John Lewis Basic Easy Fit Jeans, Blue, 8
dELiA*s by Dolls Kill Denim Cargo Pants - Light Wash/Light Blue
Bronte Jean – Country Life Fashions & Footwear
Levis 512 Slim Taper Fit Jean - Corfu How Blue
Vintage Corfu Blue 'stretchies' 90's Mom Jeans Size 18
511™ Slim Fit Selvedge Men's Jeans - Medium Wash