Politics aside, she isn't a Karen she is correct. Customer asked for a quote not the personal opinion of the business owner. All that sign company had to do is respond that he was unable to complete her order. She became a "Karen" simply because they responded in the manner that they did. The lion and sheep part was her mistake. If she omitted that her response would seem reasonable.
This story is similar to the Bakery that refused the Gay Couple's wedding cake but the Baker was considered the "Karen".