"She has black boots."
Translation:Elle a des bottes noires.
soulier(s) is an old word for shoes. Here, we don't talk about shoes, but about boots.
Yes, true. Still, I'm not a specialist in female clothes (in English to all that) and I (sadly) don't ride horses any longer, so this whole difference seems somehow slight to me. Still, OK, I agree. It wasn't a perfect translation. I had no idea somebody in a basic course would really speak about BOOTS. ;-)