Howdy,
I have no dog in this hunt, BUT as a range owner that have produced matches for over 16 years, a shooter, and for 6 years a vendor I can say that I
don't see an issue on requiring a vendor fee OR how she asked you about it. Shoots absolutely have to make money or they can't hold shoots.
Profit is not a dirty word, she or anyone has no idea (and it's none of their business) on if a vendor is making a profit on a said item, and that has no bearing on a vendor space anyway (make money if you want, and don't if you don't).
Inviting someone to vend at an event for a fee is no sin in any way. Think of how we buy things in our daily lives, sales people try to sell you every day with
"an invite to their wonderful products, for a price" otherwise there would be no marketing, just a white background ad that says "Beer $8.00" and we would all
accept that and buy it or not.
Also remember that all shoots (state and above) are run by volunteers and so the fees are not going into peoples paychecks, they are for the infrastructure and overhead costs of the events.
I truly appreciate any vendor doing something for the shooters at a zero net gain, but remember that so are the clubs and their members by even holding the event. This is just my 2 cents worth and is worth every dime paid.