I would add that one doesn't even have to consider the views of the Georgians to understand JA's meaning...a current analogy would work just as well.

Consider the difference in views regarding charity in this quite common occurance:
a homeless man sitting on the sidewalk is asking for money--one person walking by thinks, 'I'm not giving money to a man that is just going to waste it on booze'; yet the next person pulls out their wallet. Does the second person have any romantic expectations of extraordinary virtue from the homeless man now that he has some cash? Most likely, they are feeling that they have done the right thing by that man whether he does the right thing with the money or not.
I think Emma is only being reasonable in her expectations of what her small charity can accomplish, while deciding to give her time and money anyway. This certainly shows her to be extremely compassionate.