Why should he? He is working in a world where academic merits are all that counts. To earn these he needs scientific publications, either by him or the students he teaches. These publications are reviewed by renown collegues from all over the world before they are accepted into print. Where is the benefit that he could gain from his daughter's position? For an university to take on a professor who is not good enough means to endanger their academic reputation. I never read that an academic seriously has questioned why Prof. Donaldson was invited to lecture at Copenhagen university. On the contrary: as soon as an academic has build up a certain reputation, universities are only too happy to get him or her to lecture.
But normally professors of the age of prof. Donaldson don't leave their own university as they do much more than just lecturing: they perform research together with their students and do projects. That's the interesting part of being a professor: the right to research whatever you want to. But this is best done at home, at the univeristy where you have a fixed contract.
So I guess the people responsible for the maths department at the university of Copenhagen were only too glad to hear that Prof. Donaldson would be accepting an invitation. It was their chance to get him - and the loss for the university of Hobart who now have him on their payroll but he isn't there...
I see it the other way round: the fact that Mary Donaldson grew up in the household of a high-class academic who had already proven that he is one of the top scientists of the world (there are not sooo many professors for math worldwide) may have given her the feeling that it is possible to reach the top in her own profession - whatever that would be. As it turned out, she did not became a top business woman but a future first lady. The approach to both positions is the same: you feel confident with what you got in terms of talents and education, you strife to make the best out of it and if there's luck added to the mix, you can succeed.
