People always talk about 'what Art would think' and of course there is no way to know, but I can't help feeling he would be horribly disappointed in her. Even though he was just as flakey and dramatic. Even if his ego would have never allowed him to express that disappointment publicly.
The thing is, Captain, I don't think HE thought he was flaky and dramatic... but had he been well enough and lived long enough, I think he would have replaced her when he realized she was trashing his legacy in a profoundly embarrassing way. I also think he put her in his char abruptly because others turned it down, or he didn't like them, and she was available and convenient. And perhaps he was besotted, too. Who knows?