Well, obviously Mummy isn’t what most people would call ‘normal.’ Their dad indicates she’s smart like Sherlock and Mycroft are smart. The way Sherlock and Mycroft talk in TEH, I think we can infer that they were home-schooled, at least for a few years—and this makes sense, and also indicates how impressive she is. If she’s got their kind of intelligence, then she knew that no school would be able to handle them, at least till they got a bit older and learned some self-control. And furthermore a regular school can do a lot of damage to a kid’s curiosity and desire to learn in a situation like that. So yeah, spectacularly intelligent.
I don’t particularly lay down their emotional stuntedness at her door. There’s only so much you can do, with kids that smart, to help them be well-adjusted. With intelligence like that, you just never quite fit in the world, unless you work to make a space shaped like you. And like every kid comes up with their coping mechanisms, for the smart ones intelligence tends to become their sword and shield, and they tend to hide everything else behind it. I mean, sometimes in their love for their kids, parents protect them more than is good for them, so it’s possible that Mummy sheltered them too much, but I think a lot of it is down to their own experiences and conclusions (and maybe Mycroft’s influence; he seems to be a big proponent to Sherlock of the ‘think, don’t feel’ school of life).
The ‘absolutely monstrous’ line just…made me think of a mom. Because I think most moms would have that reaction.
So…’soft sweet’ old lady is kind of…I mean I think like most people, she can be. But she loves her boys and she protects her family, and she is very, very smart and that makes you capable of things, in a variety of ways.
So…ordinarily I would say that I expect more of her being Sherlock and Mycroft’s mom (assuming we see Sherlock’s family again). The only thing that makes me wonder is that book of hers, The Dynamics of Combustion. Because in the original canon, Moriarty is famous for having penned a treatise on “The Dynamics of an Asteroid.” And while I’m leaning toward the assumption of that being a charming Easter egg for ACD lovers, a corner of my mind does have to wonder…
But if forced to take a guess, my guess would be that Mummy Holmes is exactly what she seems to be. Which is a person rather more complex than a ‘sweet soft old lady,’ but I don’t think she’s secretly Moriarty Sr. or anything. It’ll be fun if we get to see more of her and her husband, though. I think they must be really interesting people, and I have no doubt that if they turn up again, we’ll discover fascinating things about them.
(Incidentally, though, that book indicates just how badass Mummy Holmes is at math. The mathematics of fire and combustion are incredibly complicated, and heavily involve chaos theory. And, since we know she gave up her academic work for her boys, and Sherlock was born in 1977, and Mycroft probably late 1960s/early 1970s, and chaos theory really only got rolling in the early 1960s…that probably makes Mummy Holmes one of the pioneers in that field.)