I agree this solve here feels too simple, like it doesn't belong in a story ostensibly about alchemy. I would have preferred she show off her genius and propose alternative components to get around the drakeskin issue.
Also, what the hell kind of weather are they experiencing that they need magical tools to keep the wet out?
Well, hurricane-strength winds are just a spring thing. There are also summer, autumn and winter to worry about.
Especially the winter - it's usually the hardest season.