Discussion on answer by Buffy: What are the ethics involved in teaching my chair's child in my undergrad class?

In any event, as written, this question is about the ethics of a student taking a course in a department administered by a parent. The answer to the ethics question is that there is a potential conflict of interest (primarily for the administrator, not the faculty), but that no ethical breach occurs simply because a student takes a class in a program administered by their parent. Yes, it would be better if the burden were shared across the department, but that isn't the question asked here.

There are many ethics codes (including some legal codes) for which the possibility or appearance of a conflict of interest is enough to violate the code.