I think this criticism is barrel-scraping
And of course she tends to visit communities other that white, healthy, privileged ones. It would be a disgrace if she didn't.
There is coverage of every single visit she makes. The Palace don't make the editorial decisions about which visits, and which shots, are carried by the media.
And I don't think the idea that she shouldn't do certain duties because black children will be there has any real support at all.