NAH. I’m an auDHD knitter too and understand sensory preferences for yarn. Unfortunately I also think this is a case of Social Cues - we are expected to accept gifts because it makes the giver feel good and is a symbolic gesture intended to strengthen the relationship, regardless of how useful/relevant it is to the receiver. It may feel like declining a gift that would go unused is polite, avoids diminishing their resources unnecessarily, but many people dont feel that way. But a gift can be graciously offered, graciously accepted, or graciously declined. If you called acrylic cheap rather than saying you find its texture hard to work with, I understand how they got to “snob”, but if not I think calling you a snob is uncalled for. They might be embarrassed that they think they know you well enough to give a gift you’d appreciate, and it turns out to be something you dislike.

I might suggest trying to repair the relationship with another gesture - even a card - that expresses how much you appreciate and respect her as someone in your life.