Depending on where you live, this might not do you any good, but here in western Canada we have Oregon Grape plants growing wild everywhere.
http://ghs.gresham.k12.or.us/science/ps/nature/gorge/3petal/bar/berberis/mahoniarepensfrt.jpg
http://wever.files.wordpress.com/2008/04/blueberries_01.jpg
They look almost exactly like blueberries. Oregon Grapes are inedible, or nearly so. They're extremely plentiful and very fast to pick because they are in bunches like grapes, hence the name.
Anyway, pick as many pails of these berries as you can and get a pound or so of actual blueberries. Take your Oregon Grapes and your real berries to a fruit stand or similar establishment (many places buy locally grown berries) and offer the pound of blueberries as a sample. If she likes them simply dump off your pails, get the cash and never come back. I pulled this off three days ago and pulled in just over $200 for about 1 1/2hr or berry picking and prep.
This largely hinges on you finding a stupid/inexperienced fruit stand owner, but theres is other ways to get rid of them too.