Muggles' Guide to Harry Potter/Characters/Amelia Bones

Overview
Amelia Bones is the Head of the Department of Magical Law Enforcement in the Ministry of Magic.

Order of the Phoenix
Harry is required to attend a hearing at the Ministry regarding his use of magic while underage and in the presence of Muggles (his cousin Dudley). Somehow, instead of a hearing, this becomes a trial by the full Wizengamot. As the magic in question was the creation of a Patronus, Madam Bones is curious as to whether Harry can, in fact, produce a corporeal Patronus, one with an actual form. When the evidence has all been heard, it is Madam Bones who calls for the show of hands to vote on Harry's innocence or guilt.

At the organizational meeting of Dumbledore's Army, a question asked by Susan Bones suggests to Harry that she may be related to Madam Bones. Susan confirms that Amelia is her aunt.

Half-Blood Prince
In the meeting between Cornelius Fudge and the Muggle Prime Minister, we learn that Madam Bones has been murdered. The Prime Minister is quite upset about this, because it happened "right around the corner", and has not yet been solved.

Narcissa Malfoy, with Bellatrix Lestrange in tow, visits Severus Snape. In the course of their conversation, Bellatrix accuses Snape of not being loyal to the Death Eaters, saying that she is Voldemort's most trusted aide. Snape wonders if that is still true, and points out that it was information Snape provided that had made the murders of Madam Bones and the Vance families possible.

Strengths
During Harry's trial in Harry Potter and the Order of the Phoenix, Amelia Bones showed herself to be fair-minded and honest. In contrast to Fudge, nominally her senior in the Wizengamot, and Umbridge, she had not prejudged Harry, and insisted on hearing the truth about Harry's case before forming an opinion. It seems that it was the force of her character, opposed to Fudge's, that allowed the hearing to be as fair as it ended up being.

When Fudge was explaining her murder to the Muggle Prime Minister in Harry Potter and the Half-Blood Prince, he described her as a highly gifted witch of her time and said Voldemort may have killed her himself after she put up quite a fight.

Questions

 * 1) Why was Madam Bones so impressed with Harry's Patronus?

Greater Picture
Although it was not explicitly stated, it is implied that Madam Bones voted in favour of clearing Harry of all charges during his trial. We are told that Fudge, Umbridge and a "heavily-moustached" wizard - among a few others - vote in favour of conviction. Madam Bones is not mentioned; therefore, we must assume she voted for clearing Harry.

This goes further towards establishing her as a character of fair and just reasoning, as she uses the evidence presented to her to make a final decision.