She could be very hesitant at first. After all, she has to maintain her professional image as a teacher. However, as time goes on, she would probably start to respond in a motherly way. For example, if Harry gets hurt during a Quidditch match, she might rush to his side and fuss over him like a mother would. And she could also start to give him advice on things that are not just related to school, like how to deal with his fame in the wizarding world.
McGonagall might be initially shocked. She's a strict teacher and not used to such an informal and deeply emotional form of address. But then she could feel a sense of warmth and responsibility towards Harry. She might start to show more care in her actions, like making sure he eats well in the Great Hall or checking on his studies more closely.
McGonagall may initially try to correct Harry, but when she sees how much he needs that motherly figure in his life, she softens. She could then become more nurturing. She might start inviting Harry to her office for tea and biscuits, just to have a chat like a mother and son would. And when Harry faces difficulties, she would be there to support him wholeheartedly, whether it's against bullies at school or the greater threats from the dark side.
She might immediately comfort him. McGonagall is a strict but kind teacher. She could put a hand on his shoulder and say soothing words like 'There, there, Mr. Potter. It will be all right.'
She might react with her usual no - nonsense attitude. McGonagall is known for being strict but fair. So she would first listen carefully to Harry's problem, her eyes fixed on him, and then start to analyze the situation. She may not show much emotion on the surface, but deep down, she's concerned for Harry's well - being.
She might be initially cautious. Given that becoming an Animagus is a complex and dangerous process, she would likely want to ensure Harry fully understands the implications. She could start by asking him why he wants to become one.
One possible plotline could be that Harry, feeling a lack of maternal love in his life, subconsciously starts seeing McGonagall as a mother figure. This could lead to him seeking her advice more often, not just about school matters but also about his personal struggles. For example, he might go to her when he's having nightmares about Voldemort instead of just his friends. Another plotline could be McGonagall initially being taken aback by Harry's behavior but then gradually warming up to the idea. She could start to protect Harry even more fiercely, like a mother bear with her cub.
Harry might be initially shocked and confused. He has always seen McGonagall as a reliable figure in his life at Hogwarts, so her abandonment would be a huge blow to him.
She might use her magic skills to shield Harry from physical harm. For example, she could cast protective spells like a strong shield charm when Harry is in danger from dark wizards. Also, she may use her authority in Hogwarts to keep him away from those who wish to harm him, like making sure he is not alone in dangerous areas of the school.
McGonagall often serves as a mother - like figure in fanfiction. She might comfort Harry when he's facing difficulties with Voldemort or other challenges at Hogwarts. Her influence is seen in how Harry approaches problems. He learns from her to think calmly and use his wits, rather than just relying on his Gryffindor bravado. This helps him make better decisions and grow into a more well - rounded wizard.
McGonagall might notice Harry's distrust and feel hurt or frustrated. She may try to figure out what went wrong but find it difficult as Harry is not forthcoming. Their interactions become less warm and more formal. For example, in class, Harry may be less likely to ask for help from McGonagall, and McGonagall may be more strict with Harry as she doesn't understand his change in attitude.
In most proper Harry Potter fanfiction, McGonagall is a strict but fair character. If Harry were to break school rules in a fanfic, she might punish him as she does in the original books. However, it depends on the plot and the writer's interpretation of her character.
She might be horrified and immediately take steps to protect Sirius. For example, she could confront the abuser or report it to the proper authorities within the wizarding world.