Where to buy narrow Size 12 us 10 uk women's men's heels
Amazon.com
The Amazon Essentials brand does fashionable styles at great prices up to size 15 US and they've a good range up to size 12/13 us including Sam Edelman, Naturalizer and Journee. For sizes 13-16 us, they tend to be either Chinese brands or unisex. If you have Amazon Prime, many shoes have free, fast shipping. Plus you can even try before you buy.
Specialist large size shoe store in Quebec also selling online to Canada ($10 flat rate shipping) with a wide range of women's shoes in sizes 10 to 15 US, with selected fantasy styles up to size 17 US. Large selection of brands and styles. They even do rain boots, slippers and socks. They are happy to advise on the right size for each style if you send them your foot measurements before ordering or during checkout. You can also visit their shop in Rue St-Hubert, Montreal. Website is in french.