Something that you may want to consider is having some made to measure clothing made. There are quite a few companies on Etsy and places like that that will make some clothes for you for surprisingly cheaply.
Shoes wise I’ve had the best luck with torrid, Long tall Sally, and empress. But I think 15 might be hard. If you can get close, a cobbler may be able to stretch it the rest of the way.
Lastly, even if you have to purchase men’s pants, you can always get them tailored to a more feminite cut.