When writing about your most recent act of generosity try to make a rough essay plan first, because this topic takes in a lot of specialisms. One relevant study area would be Social Sciences where students can talk in terms of social deprivation, charity commissions and the ethics of tax deductions in relation to charity giving - and also reductions of government subsidies to charities. Many charities for example, can be affected by political mood when it comes to giving, particularly when charity or even social welfare is coming out of the public purse paid into by the tax payer.
So try to work out the point of the generosity question first, and then look for examples from your exoeriences that fit the subject you are studying. The question is probabluy designed to get you thinking about the concept of generosity itself - and may lead to further work or essays on socio-economic groups such as the 'deserving poor' as opposed to the 'undeserving poor.' Find an example where you had to think your generosity through first(typical dilemmas might include whether a musically talented busker is entitled to a few dollars for his enterprise and diligence whereas a homeless person begging might be perceived as just a 'bum' or a lazy addict who will just spend your hard-earned dollars on more drugs or alcohol. ) Either way, these are tricky questions designed to get you thinking about the whole ethical debate about need, welfare, religious motivation and charity.