Is it always the same sweater she brings? I've had kids in the past with sensory issues ( touch, taste- they were also picky eaters and didn't like certain textures). I found any clothing that was bunchy or clingy were bad -bib snow pants and bathing suits were two I had trouble with. Switching to snow pants without the bib for one child worked better, and the other child I suggested to mom trying a swim shirt which worked.
Maybe ask Mom or Dad if another sweater or jacket could be sent? Just an idea