There is a saying in English: "Charity begins at home." This means that familial obligations should be met before any outside causes.
Luz would have us believe that some (all??) of the royalties from Amaral's book have been donated to a charity. No matter how worthy this charity, commonsense indicates that it would have been far better (and more honest) for him to have used that money to secure the roof over his family's heads, to mitigate his debt to his brother, and to pay his back taxes.
However, one remains sceptical about this so-called donation to charity, given that Luz refuses to state her source for this claim. Far more likely,IMO, that any such "donation" is merely a scam to hide funds from various creditors, and an attempt to avoid a possible damages payout at the end of the libel trial.
One has to wonder why Luz has publicly revealed this possible donation, given that she herself has stated: "Why should I reveal something that he wanted to keep private?" If she knows he wanted this matter kept private, why has she ignored his wishes, and then refused to reveal her source for her claim? All she has achieved is to further diminish his already tarnished reputation for fiscal responsibility.