Is it wrong to give a streetwalker flowers and a card for her services? In addition to cash of course?

It is a little odd, but I am sure that they would accept the token of appreciation.

My experience with streetwalker's is limited to doing a lot of streetwalking of the traditional walking variety in San Francisco, where talking to propositioning prostitutes seemed mildly amusing at the time, and a half dozen or so trips to Tijuana, where the prostitutes make themselves known at every turn. They literally throng you. I still remember walking across the pathway linking San Diego and Tijuana talking to random dude who told me he made the trek frequently only to indulge in the prostitutes. Whatever. The variety of the human condition unceasingly tickles my brain. Yeah, so I've never given a prostitute either cash or a gift or anything else. But the ones I talked to really couldn't care less about the prospect of getting a gift. They weren't looking for a date, a Julia Roberteque escape from their lifestyle, acquiring gifts, or really anything more than getting cash. It's bad form and a waste of your time to do so, I'm convinced. I offered to buy one a beer in Tijuana for the conversation and she had no interest at all in that. So I left.