Based on my current understanding of VA state law (which is actually minimal at best... lol.) It is possible to be a professional Dominatrix and NOT be a prostitute. The professional Dominatrix is a profession such as a hair stylist... they offer a service for an agreed upon price, etc. As long as she does not have actual physical intercourse (which would/could be open for each persons own interpretation) she is not a prostitute because no actual "sex" was involved. If she did have sex with someone, to stay within the letter of the law, she would need to not charge them or it would be considered prostitution.
My personal opinion on the article, if it is accurate... she wasn't discreet, which only added to her troubles. Bottom line though the article was written for the sensationalism of it. That is what annoys me the most... everything written on D/s is normally written for the sensationalism and to inflame people's dislike of what is different.... grrrrrrr.