I know here in the states just posessing Marijuana is illegal, but making it or being caught smoking it is worse. I'm not sure if she was a prostitute or not, but perhaps the madam of a prostitution buisness. It said she ran a "bawdy" house.
In a way, soliciting her services to a neighborhood man could be considered prostitution by some, even if it was for Domme services with no sex involved. It said that the complaints came from neighbors. Perhaps they were mistaken about her simply being a Professional Domme and thought she was a kinky prostitute instead.
And yes, I think it's possible to be a Professional Domme without being a prostitute, but I'm sure there is liscensing and such involved. I know there was an episode of CSI that dealt with a professional Domme and the business she ran. (One of my favorite episodes.) But it wasn't that she was commiting a crime by being a Professional Domme, but one of her girls ended up dead.