There was another thread talking about this a couple of days ago I believe, but MNHQ removed it as people believed the OP was a “troll”.
I find it horrendous, to be honest, especially with the amount of support they're receiving. Apparently, they've removed the clip now where they mention the cold showers but I haven't got the heart to go and check as just seeing that poor baby looking so solemn breaks my heart.
Another thing to notice is when the father brings the toddler back, he's clenching his hands, rubbing them together, as if they were freezing, and then he claims the water was “tepid”? 
It's not just abuse, though, is it? It's blatant classism. The only reason they're not being investigated is that they're popular vloggers, with a large home, a plethora of toys, and their fridge is packed with food. But if it were a family that didn't put their children's lives on the internet, lived on a council estate with just the bare minimum, those children would have been taken away promptly.
Of course a 2-year-old doesn't understand what she is doing to deserve such a distressing, inhumane punishment. There would be absolute uproar if it had been a dog, but it's all right because it's a toddler who, according to their fans, "should know she's being naughty" and "needs to learn the consequences of her actions".
Thankfully a lot of people aren't just sweeping this under the rug. I hope this stops their exploitation of their children and they're finally taken down or demonetized.