This is not Ms. Markle’s problem. It is the organization’s problem, and the UK government’s problem, to the extent that they funded the activities. She did not do anything wrong in promoting a NGO that she had no reason to believe was doing anything but helpful work.
She was a “goodwill ambassador” which is an honorary title. Yea you go on a trip or two, have some publicity pics taken, maybe make a speech, and since it was a British funded charity that seemed to be doing good, she probably didn’t think there was any reason to be concerned. It is not as if she ran or managed the org. The question is will she step down from the role - probably.
Some people seem have a visceral hatred for her that I don’t quite get. Some people likewise hated Dianna. But I think Markle being an American and being bi-racial is at the root of a lot of it.
The stink sticks to her because she gave her support to an organization she didn't vet. She may learn, she may not. Sounds like you've got a dog in the hunt too.