Yep, I'm a keen cyclist. Well, was - baby number two is 12 weeks old and I haven't been on my bike since February of this year when my bump was getting too big!
I really would recommend trying a bike in a bike shop if you can. I was convinced that a Specialized Dolce was THE bike for me until I rode it, I bought a Trek WSD in the end, but was also tempted by a Bianchi.
The women in my cycling club are all completely different shapes and sizes, and range from teenagers to octogenarians! All wear whatever is most comfortable for cycling, not what looks best. I do wear (some) lycra for the functionality and I admit I don't look wonderful in it.
As mentioned above I have a Trek road bike, that's my going out on my own fast(ish) bike, but I use a mountain bike with slick tyres for my everyday carting children around bike as it's more stable with a baby seat on the back and has a sloping top tube so easier to get on and off without hitting said child.
I do use SPDs on my road bike - I think they're great, more efficient pedalling, better positioning etc. They're really easy to get used to as well, you can adjust the release so that it's easy to get your feet out. Oh, and expect to come off a couple of times while you are learning, it's part of the deal! I don't use the SPDs on my mountian bike.
It's a good idea to join a club if you can - good motivation, meet new people and discover routes you never knew about. They're usually a good source of spares and advice on all sorts of things too.
Hope you get some more useful suggestions. Enjoy!