It's easy to just dismiss her as an evil psychopath, but I think it's worth considering that she is exactly what happens when parents of special needs kids have no outlet and no support. She's the sole caregiver for a child who has pretty severe microcephaly and is in diapers, at the very least. It's not an excuse for hitting him, ever, but I wonder when was the last time she had a few quiet moments to herself. When did she last get a shower? A cup of tea that was still hot? A full night's uninterrupted sleep? When did someone last ask her about how she's doing, rather than framing the question in terms of her child's health? If she gets sick, is she able to go to bed, or does she have to death-march through her day because nobody else will care for him? Does she lose sleep worrying about what will happen to him when she dies? Does she ever get to have an adult conversation with an intellectual equal, or is she isolated with her disabled child all day? Does she wonder whether he can love her back or whether he even cares that she feeds him, changes his diaper, cuddles him? Is she even a person anymore, or does she only exist to care for his every need, without thanks or recognition, until one of them dies?
It is never acceptable to hit a child, especially not one who cannot cognitively grasp why he's in trouble. However, I think it's really important to discuss how isolating, numbing, and frustrating it can be to parent a disabled child. There's very little support out there for parents, especially outside the Western world, and even then, it's largely taboo to express frustration or say you don't want to do this anymore. Everything must be positive and inspirational at all times or you're a shitty person who doesn't deserve to have a child. She's going to get absolutely destroyed in the comments, but I think what she really needs is compassion.