IO, I had the same kind of neighbour once! She was a retired stock broker and would ask for ANYTHING if it suited her. My wife and I drove her to her doctor's appointments, babysat and shampooed her dog, planted shrubs, geesh the list goes on and on. And all without as much as a nickel in return. She even bought the house next to her because "she wanted to control who her neighbours would be".The icing on the cake came when she emailed my wife explaining her nephew was going to private school, she was going to have a yard sale to raise money for him, and could we bring over stuff for her to sell??? We were a young family, two kids(under 6), one with cronic care needs and only one income. My wife blasted her back and told her she should be ashamed of herself, knowing all well our predicament and asking for goods as well as physical help. No response, no apology, no thank you for what you've done, zilch. The free ride was over I guess.
Tell her nicely to bugger off. People like her know that they're being rude, selfish and taking advantage of you but just don't care.