Two Quick questions involving previous Harry Potter books

Seriously, if you can't remember who Umbridge is then it's time to reread the last couple of books. You really miss out on stuff if you can't remember the details of the other books. I remember when I got Order of Phoenix. I started reading it and 2 chapters in I realized I couldn't remember half of what happened in Goblet of Fire. So I had to reread it first. When HBP came out I reread OotP because the details were fuzzy. A couple months ago I reread both of them again in anticipation of Deathly Hallows, that way when I actually got the book the rest of the story was still fresh in my mind.

Dolores Umbridge was the Defense Against the Dark Arts Teacher in "Order of the Phoenix." She was appointed by the Ministry of Magic because Dumbledore could not find a suitable teacher for DADA. She was a mean, cruel, and sadistic witch who trampled on the rights of students and teachers alike. The scars on Harry's hand say, "I must not tell lies." Umbridge forced him to write these lines using his own blood for ink during his detentions.

Yes, she gave Harry those scars. She was installed as the new Defense Against Dark Arts teacher by the ministry, mostly because Fudge was convinced that Voldermort had not returned. Rather, it was a tale Dumbledore told to be able to take over the ministry by using his students as an army. Umbridge is given powers over the students and teachers, is VERY cruel against anyone who doesn't do as she says, and attempts to defame Harry. Whenever he protests against her lies about Voldermort or her prejudice against anyone not a pureblooded wizard, she forces him to use a quill using his blood as ink, carving the words he writes into his skin.