double sticky tape on the chair at the place she likes to scratch should deter her - you shouldn't have to leave it in place forever, but it will take some time - enough to get her to stop and lose interest. (Thank you for not declawing!!!). If you can move the chair that might help too - if its a place the kitty feels is a border she might really like marking her territory there.

Sometimes they just love the paw feel... my dining room chairs have woven fabric backs. My cats made a total mess of them (but have left all the other furniture alone thankfully - they really like to scratch the big wooden support posts in the basement and the wooden IKEA shelving units we have for storage down there - scratch on kitties). I recently made new covers for the chairs of a pretty normal slick fabric and voila - the cats no longer touch them.