Upload & Sell: On
What was her recompense for holding the sign for you (I can't imagine that was her pristine piece of paper, nor 'her' statement)? The standard $1 and sign the release? The look on her face makes it look like she's doing something she doesn't particularly want to do, but 'has' to. Did you also give her the beer for dramatic effect?
I have to be honest here, I'm all for making social statements via artwork, however doing so at the expense of one who's on the short end of the stick doesn't do anything for me. I'm not in the least saying that street photography nor images of the homeless inherently imply taking advantage of those who are less fortunate. Had the sign been taped to a piece of cardboard, tattered from the elements, and not been printed in greyscale to save ink (who's ever seen a grey bar code?) I'd be a bit more open to it.
This image says: "Here, hold this for me while I take your picture; I'll give you a buck..." I feel bad for her, but not for being homeless, and I don't think that was your message...
Maybe I've read into this too much, but it's just my impression of the image, and sorry if I've offended you in any way.