At work I wouldn't want to walk slowly really, got work to do and shoes are the least of the worries.

Nope. We're in an office. All work is done at our desks. Walking plays zero part in our productivity. Meaning that any time she gets up it is personal. Still not bad manners to try and eliminate the amount of trips she has to make to get that cup of coffee?

And some heels just have a loud clomp regardless of any feet gymnastics you do.

But that isn't the worlds' problem. She chose to wear them. She should take responsibility. If I don't take responsibility for my own actions and put them on other people that isn't poor etiquette?

If they're just walking from A to B, I'd say just deal with the noise.

Again, not my issue. She chose to wear them. That's what you;re missing. I shouldn't have to deal with it. That's why it seems like bad manners. Forcing coworkers to deal with your bad habit is very rude.

If they're at their desk, stationary, and are fiddling with their feet then politely ask for them to stop

Can't do that or I'll be called a bully and taken to hr.