The women I know all ride men's bikes, including me. If you can get on and off the bike comfortably, a men's bike might offer more selection on Craigslist. Those Breezer bikes are a lot better than the big box store bikes. If it is within your budget and the bike fits, it would be a good choice.

Remember to budget some money for gear. Helmets all have to be certified so even the inexpensive helmets will provide the same level of protection as more expensive ones. You might also want a basket, water bottle and I do recommend gloves which can prevent road rash.

Welcome back to the world of cycling!