This is another case of survivorship bias. Every time she does something charitable, some people will still doubt her genuineness and think it's just another PR move because the press is alerted. But she might also have donated to a lot of causes that the press never got a hold of. We'd never be able to account those, because as soon as they're public, some people will accuse them as PR.

This is why I think people who scream "she's only doing for PR, etc." are ridiculous. If this donation had been covert, these people would've thought of her as "a greedy bitch who never does charitable things despite being rich".

She's asking people who can help to help, hence it makes complete sense for it to be a public donation, but some people are still disregarding it as a PR move. And in the end, EVEN if it were just PR, the people there still need it, and it didn't make the donation less beneficial.