This is going to sound bizarre, but bear with me. Maybe it's because I'm from Sydney, Australia, the home of the Gay and Lesbian Mardi Gras...
We have a number of female performers with big feet. One in particular, Rhonda Birchmore, is very feminine, a dancer and singer. So she HAS to look good AND be able to move around in what she buys.
She has openly admitted to buying her shoes from a shop that specialises in really glamorous shoes for drag queens and transvestites. We have a few shops in Sydney that are worth looking out for someone like Rhonda. And they love her to bits, as well.
So my suggestion - for really special shoes with extra "bling" or pizazz, check out suppliers for drag queens and trannies. And for sports shoes, they may also be worth a look, there has to be a market for larger shoes, for women (or those who want to look like women) that are not so over the top.
And yes, they WOULD specialise in mail order because a lot of their customers, by definition, are shy.
Marg