While I do agree with the general sentiment, I think this is nowhere near as bad as other recent appointments, given a) that she's getting relatively little money for it,* b) the subject she's been brought in to tackle is one that is often overlooked and does require tackling and reform, and c) she does appear to actually be qualified for and passionate about the job.
Perhaps there should have been an interview process, but this doesn't strike me as "let's find a way to bung you some money, shall we?" but more as "you're talking a lot of sense. I think we could do well by hiring you".
The majority of job hires come about through knowing the right people. Sometimes that can lead to unqualified people getting jobs because their mates are in the position to give it to them, but it can also mean that people get jobs that they're suited for because the people in the position to hire people already know their ability and their character. This strikes me as much more akin to the latter than the former.
*£8,400 a year isn't nothing, certainly, but it's not the more traditional millions, either.