Parts of this are word for word from the first book which I own a copy of but nothing more in case you thought I did.
"The man whose transfiguration you cancelled is called Peter Pettigrew. He was a friend of your father while they attended Hogwarts. We had previously believed that another man, your Godfather Sirius Black, was the Secret Keeper on the night of your parent's deaths and had betrayed them and killed this man. The Ministry of Magic had the man you uncovered have an emergency trial under Veritaserum- a truth-telling serum- to discover the true events of that night. It has now been bought to light that Peter Pettigrew was the true traitor and that your godfather had proposed the switch so that his family could not make him reveal their whereabouts. As Sirius Black had been believed to have caused the deaths of your family- particularly as they were a well-respected family- he had been admitted to Azkaban. Headmaster Dumbledore is doing his best to speed up the proceedings but there is hope that your godfather can be released and his name cleared relatively quickly. The Minister doesn't want to seem unjust but he is currently protesting against the quality of the Veritaserum as he does not want the public to know someone has been wrongly imprisoned under his nose." Harry just stares at her.
"I don't know anything about my blood family." He admits. The teacher looks at him, incredulous then worried.
"Your relatives never told you about your heritage?" The boy shakes his head.
"No- I was only with them for a few years. I asked once and they told me that my parents had died in a car crash while drunk which left me with the scar." He gestures to his forehead and McGonagall schools her expression into something more neutral.
"Where have you been since then?"
"Well I was running away from my cousin and suddenly found myself in America one day and a woman decided to take me in." He says their agreed cover story without thinking and the Professor just nods.
"This woman treats you well?" Harry nods.
"Yes. She is the sheriff of her town and has two daughters whom she picked up off the streets too. We all get on well and mom covered up my accidental magic really well." Professor McGonagall frowns.
"The laws in America are rather constricting I have been led to believe. I would still be more comfortable if I could meet your family. Especially when your godfather has been released from Azkaban I believe he would like to know you have been in safe hands. Would it be possible for me to arrange an appointment with your family?" Harry thinks.
"I think so- I don't know if mom would be willing to leave her town for too long but I know she would be interested in meeting one of my teachers." The Professor nods.
"I will have to tell Headmaster Dumbledore about your change of location but I will arrange a meeting with your guardian at the soonest convenience. Would you like me to tell you about your family?" The boy looks at her, drops his gaze to his wand on the desk in front of him.
"I think," He starts, "I think I would like that. Thank you." The Professor smiles fondly.
"Very well then. I will save more for our next meeting as I expect we will be having many more and it is getting late. For now I will tell you that your parents are Lily Evans and James Potter and that when they started at Hogwarts they hated each other very much." She dismisses Harry then who wonders about how his parents ever got together if they hated each other so much all the way up into his dormitory.
Everyone else is sound asleep so Harry quickly changes his clothes for bed and closes the curtains around him.
Rowena stands, rotating her back slightly.
"You go to sleep quite late even with the time difference. I've been waiting for a while." The slight frown changes into a smile as she looks down at the boy.
"How are you this evening Harry? Learnt anything new today?" Harry answers the questions quickly, hoping they can get past the greetings without too much delay.
"I'm fine. I've learned lots today in Transfiguration but the other lessons were things I already knew." The older witch smiles proudly.
"That's my lad- I told you you'd run circles around them!" As she speaks she bends down, brushing imaginary dust from Harry's shoulders, "So, what's got your tongue? There's something you aren't telling me Harry." The boy nods and sighs.
"One of my teachers here has already guessed that I was taught by someone else. She said that I must have been taught by an old master or one of their apprentices. She didn't make me tell her but I don't know what to do if someone does find out anything more than I have been taught. She advised that I tell no one about my skills." Rowena takes everything in with patience. When he finishes her eyes close and she grimaces, bringing a palm to her forehead. The witch breathes in and out before fixing her gaze back on Harry, jaw tight.
"And she offered to tutor me if I have anything I want to learn that she knows." Rowena nods, taking a few more seconds to think.
"So. There is nothing a wizard of your current knowledge can do to erase her memories and if she recognises your skill she has it herself this means she might have connections to the people after me. If anyone else asks you just say your family friend taught you- most people don't care enough to ask more questions. Her advice is good but I don't think you should trust her either. What does she teach?"
"Transfiguration." Harry replies. The witch frowns.
"In that case I would suggest you take the extra lessons because that was never my strong point. Would you like to practise it now?" The boy smiles.
"I would- thank you Auntie Rowena." The space around them changes into a stone walled room, wooden desks and chairs spaced evenly throughout it. A matchstick, a feather and Harry's wand are on the desk in front of Harry. Rowena looks at the wand in mild disgust, picking it up between two fingers and scanning it intently.
"You might want to try without using this thing. If you use it too much you might get too used to it and not be able to control your magic so well without it." She drops it back to the table. For a second Harry looks at it then nods.
"Okay." He wraps his magic around the matchstick, surprised at it's easy response. In almost no time a perfect needle sits on the tabletop, no lingering threads of magic. He definitely shouldn't use his wand if results like this happen outside his dreams too. With a light tug the needle returns to its original form. He tries several more times in case it was a fluke. Rowena observes curiously.
He tries with the feather too and the results are the same. He doesn't know why he didn't try it earlier actually- obviously it would be easier for him to use his own magic rather than directing it through a wand because that's what he is more practised at.
"Is your transfiguration limited to turning one inanimate object into another?" Rowena asks. Harry turns to look at her, grinning.
"I don't know."