Probably the same as other artists who appropriate work... nothing.
As for editing other people's work... that's not a copyright issue, that's a moral rights issue, and you have to specifically state that you are asserting your moral rights in writing. Even then, the press and other publishers can effectively ignore moral rights quite legally anyway.
There is a moral right issue here, and a potential copyright issue for the original authors, but I suppose it's whether they are A) still alive or have someone in charge of their estate that is bothered enough to act over them being re-published, and also B) If she's making any money out of these images. Some people just aren't bothered about whether people use their images until money raises it's head, particularly such famous ones that have been in the public domain for decades.
The other matter we're guessing at is whether she has obtained permission to do this... which she may well have done. I know this isn't the first time she's produced wok like this.
