You may know, I am an Italian. A 17-year old person is not a child -in Italian, "child" means person below 14 - and she was certainly not a child over the subsequent years when her family waged a campaign claiming a politically motivated conspiracy, and when her father left politics following the case.
People are members of some family, and she took her father's place in politics. She did not put any distance between herself and her family actions, and the accused murderer happens to be her brother.
It's not a matter of judging her, it's a point of knowing where she comes from. How could I ignore the analogy and methods between her family case and political campaign calling a politically motivated conspiracy theory about police, and the case she stuck her case into with its political campaign callign a conspiracy theory? Why should I trust her or consder "respectable" in this regard?
On the other hand, let's say that another element to consider is that her observation was not a rational critique but rather a rabid delusional rant, a nonsensical accusation of political motives against decent persons.
The reason why she waged her vicious accusation might have something to do with the fact that she is a democratic senator from Seattle, that is from the same city and same political environment of the FoAs, the crowd that includes Ann Bremner & Judge Heavey and the Seattle Prep lobby group, the same people who gather with "brothers" at Vashon Island and a local family that includes Gogerty Marriott and his campaign, to which even Douglas Preston came to give its contribution and managed to drag the ICJ into.
Cantwell jumps into the case not because she has any rational critique to make - on things she has no clue about - but because the FoA managed to put up a political force of influencers around the case and Cantwell was just pushed by the political sentiment they created in her local environment.
Cantwell could not "refuse", after all. Since, you know, the case of her brother was still there...