If that's what she wants, and her husband is willing to support it, then I think it's entirely up to them, and no one else. It doesn't sound as though she never bothers with her children at all - she's with them as much, if not more than many full-time working parents. And that's not a pop at working mothers - I am one!
However, since she's chosen to broadcast her thoughts and feelings on the subject, and is presumably content for people to give their opinions, I personally don't think I'd have much time for her, because it doesn't seem like she actually does much with all that time that the nanny frees up for her. It just seems like a massive waste.
If I knew someone with a full-time nanny and plenty of money, I wouldn't judge them if they were doing interesting things with their time - hobbies or sport or renovating the house or anything interesting - I'd just be hugely envious! But if they were just frittering the time away and having nothing to show for it but nice hair and handbags, then yes, I'd probably judge - but I'd judge them as a bit lazy and lacking in imagination, rather than as a bad parent.