[Hartford, CT] [First Grade] - Any recommendations on professional clothes for women you could bike in?

So, I love biking to school in the mornings. I only live a few miles from the school, and the fresh air and mild exercise invigorates me and (I think) makes me a much better, happier, and more energetic teacher.

Anyway, this morning one of the other teachers pulled me aside and told me she doesn't think I look acceptable when I'm on my bike. It's Friday so I wore jeans and a school T-shirt, but most days I just wear some modest leggings and a T-shirt, then throw on a dress in the bathroom once I arrive so I'm dressed for the day.

Anyway, I'd really like to keep biking to school. My students love seeing me on my bike, it makes me happier and healthier, and my car sucks. But I don't want to hurt my reputation or career. So, if anyone can recommend some other outfits, I'd really appreciate it!