Note: This post will contain Cursed Child spoilers.
Ask me who my favorite Hogwarts professor is and my automatic response will be Professor McGonagall. While I consider both Remus and Hagrid to be in my top ten favorite characters, they're not the ones who immediately come to mind when I think of Hogwarts professors. Remus was an excellent teacher, that much is true, but as he spent the majority of the series not teaching, he doesn't come to mind as quickly as Professor McGonagall.
Not only is Professor McGonagall consistently there as a professor throughout all seven books, she is an excellent professor on top of that. I honestly believe she exemplifies so much of what you want excellent teachers to possess. She's always there, and she cares. That may not have been incredibly obvious to me when I read the earlier books for the first time as a kid, but I recognize it now. I don't want to go so far as saying that she's the most caring professor in the story, but I think she's one of the professors who we get shown that caring side of the most in the series. Hagrid might be the only competitor in that regard, but we really only see Hagrid caring about Harry, Ron, and Hermione, not his students as a whole. Whereas with McGonagall, you get a sense that she cares a lot about, if not all, most of the students that she is tasked with teaching.
One of the most heartbreaking moments of Cursed Child for me was when Harry got angry and snapped at McGonagall for not understanding because she doesn't have children. This clearly affects McGonagall who remarks, "I'd hope that a lifetime spent in the teaching profession would mean..." That moment got to me. After seeing McGonagall be there for Harry throughout all seven Harry Potter books in many ways, seeing the way Harry's words affected her was saddening. It's even more saddening because I know that Harry recognizes the way McGonagall has cared for him too. We do see him apologize to McGonagall later, but I wish we got to see just how much he regretted saying that to McGonagall because I don't feel like we see much deep-seated regret within the book itself. (This is something that could depend on the actor's portrayal of the moment since it's a play.)
While there's often a greater focus on, say, the ways Dumbledore cares for Harry than there is McGonagall, I don't want McGonagall's actions over the course of the series being discounted. She's not often included in lists of parental figures in Harry's life, and I think there's a good reason for that. She's not a parental figure; she's a teacher. But I think that it's just as important that Harry have had an important teacher figure in his life who cared. (Maybe I'm a bit biased in that regard as a teacher myself.)
Never having kids of her own does not in any way discount McGonagall's influence as a teacher. I know she's had an incredible impact on many of her students' lives. You can see it in how she's portrayed in the books and, particularly, in the impact she has on Harry. I know Harry knows that too regardless of what he said in Cursed Child. Maybe he didn't recognize it as a kid, just like so many of us don't realize which teachers had the most influence on us until we're much older, but he did eventually realize it. That much is clear by Deathly Hallows when he so readily stands up for McGonagall against the Carrows. He didn't do that because her impact on him was small.
So this post is dedicated to Professor McGonagall. She deserves it.