in your dreams
I think the proper response is “…and then you pee the bed and wake up.” 
Try Googling [your city] Bicycle Coalition. If there’s one nearby, they probably have some resources to help you find stuff like that. Here, the SFBC is huge, but at the same time it’s pretty informal, and everyone tries to help others out, whether it be safety or laws or good bags or whatever.
And yes, there are tons of people, male and females commuting on bikes here.
I cycle to work here in Melbourne Australia, and I’d also say the split is 50/50 - fewer women on road bikes in lycra it must be said (I don’t care, lycra makes me go faster!), but lots on hybrids in their work clothes.
I know you said you didn’t like shopping online, but I’ve had great success with Team Estrogen- great collection of women’s specific bike gear, and a good forum too.
I am the opposite of athletic, but inexplicably get this catalog in the mail sometimes. It has really attractive activewear for women (not exclusively cycling).
I’m a woman cyclist! I only live a mile from work so usually walk – when I do bike it seems like I spend twice as much time getting my bike out and locking it up again than I do riding. But I do bike most other places when it’s not too cold. I feel like there’s about an even gender ratio for cyclists here, although I do live in a small cycling-crazed college town.
There are three bike shops in my town. I shipped my bike to one of them when I moved here and when I went to pick it up, I could not get any of the all-male hipstery staff to help me. I stood at the counter for about ten minutes. When I finally caught someone’s eye he said “oh I thought you were with him,” pointing to a guy next to me. Ugh. I now go to the only bike shop that has a woman on staff. Everyone who works there is super friendly and approachable.
No, it is not because you are a woman. People in professional bike shops are dicks to everyone that isn’t in their weekend “peloton”. I have been riding longer than any of those folks, I was into serious cycling before it was popular in the US, many years ago, and it was as true then as now. Sad to say, all “serious” riders are complete d-bags. I am the only exception. 
You don’t fit into a small “mens” size?
I got a nice “Motobecane” Century Comp from Bikes Direct. A lot of people decry the outfit, but so far so good. They use generic Chinese frames and paint them with fallen flag brands that they bought the rights to. For much less than a name brand I have nice components, composite frame, a sweet ride, all in all the best bike I have ever owned. I got all my accessories from Wal-Mart and Target for things like trip computers and water bottles, and a real nice pair of Shimano shoes from REI.
REI is a great outfit, and they don’t treat you in a condescending way like they do at most of the bike shops. The salesmen are really experts in their departments. If there is one in your area, do check it out. They also have a very full line of outdoor gear for all kinds of activities and their store brand stuff is first quality at very fair prices. I would stake my life on their backpacks, etc.
Here in LA, we are seeing a lot more bike commuters, including women. LACTMA, the local transit agency is doing all it can to accommodate mixed mode commuters, with racks on the front of buses, taking out seats in the rail cars to make more room, adding bike lockers at stations etc.
Speaking of staking one’s life on a backpack, I was using a cheapo backpack riding my bike to school years ago. It was stuffed with heavy textbooks, and one of the shoulder straps came undone at the top. The pack swung one way, I swerved the other in a classic example of Newtonian physics, and I swerved to the left. If a car had been coming, I would not be here to type this post. Please do get a high quality knapsack from a reputable outdoor gear manufacturer like Jansport or REI if you go that route. This applies to everyone who may read this post. That “Hello Kitty” special from K-Mart can kill you on a bike.
I wouldn’t do that ride and I’m pretty traffic savvy. Can you find a back route that might take a few more miles (more exercise :D)? Or, for 3/4 mile, walk?
A coworker rides her bike in every morning at 4AM :eek:. Rain or shine. She’ll only not ride if she keeps falling off due to ice (but she’ll still try).
Often the cut is wrong for women. I ordered a shirt online and they screwed up the order and we got a small. My girlfriend wears it because it fits, but the cut is definitely and noticeably not designed for a woman. It looks boxy on her, but that’s okay, she likes it that way. Jersey’s cut for women come in at the waist then flare a bit to accommodate hips while still having a snug fit. The guy’s jersey tend to ride up on her a bit because it gets a little bunchy at her hips.
Compare this men’s cut jersey to this women’s cut jersey.
Oh, and we order stuff from Nashbar.
ETA: Nashbar was NOT the company that goofed up and sent the small jersey, that was someone else.