R.B.
yes I would still tip her if you are happy with the service she provided. A tip is a reflection of her services.
Yes she owns the place and its out of her house and she sets the prices... but those prices are in place to cover all the supplies and get enough for an "income" to cover all of the monthly bills she has. A tip is extra money in her pocket and not part of her income... just like everyone else you tip out there.