To those saying that the mother humiliated her across the internet - actually, that was the media.
If the mother was more responsible, she'd know that the media would pick up on this. But hey, I guess it's not a big deal for her and perhaps she's got a different idea of what shame and humiliation is if twerking is too much and this is.
I don't understand how this relates to the OP. The mother says that the girl has done the dance previously, and was told it was inappropriate and sexual, yet she continued. How is that hiding any truths? The girl new exactly what she was doing.
There are many different ways of getting someone not to do something. If her kid was just told that it was "inappropriate" and "sexual" - unless she's one of those obedient-type kids who listen at the drop of a hat, it's not going to work. And she's clearly not that type of kid. At that age - even for me, I'm a dude too - there is a big dissociation between hearing what "sexual" means and understanding what "sexual" is. And there's also a similar dissociation between what she did and her punishment, she'll know that her mom would punish the crap out of her, but she still doesn't understand what twerking means for her mom - this isn't teaching her any empathy.
To me, this is an example of fighting a battle to win the battle, instead of trying to win the war. I guess mom promised a punishment, so she feels like she has go on with the deterrence - well A) it wasn't much of a deterrence, and B) it wasn't much of a constructive punishment either. Maybe it's okay to do this just once (not the ridiculous attention-
seaking seeking fashion she did it) to maintain her parental authority, but again her battle plan is not working and should be changed, and now she has to deal with the fallout from this punishment which she may or may not have prepared for. One does not punish simply to punish, but to teach. It's not about outlining a set of artificial (compared to the real world) conditions and consequences for the child to follow but, as parent, to continually adapt and communicate to get the message across.
What her mom should have done is sit her down and have a talk about it, get her to think about it herself, get her to question her motives. I don't know if that'll be getting her kid to grow up too quickly since a lot of kids do whatever they do without thinking about it, but if she's looking for maturity that's a way she'll get maturity. This has to be built around institutionalizing proper rapport and frequent communication and confidence building exercises (I'm taking this from international relations, but it's been an apt analogy so far), it's better for her kid to feel confident that her mom isn't going to shame her in any way if she happens to be influenced by peer pressure that day or whatever. If obedience is an issue, then it's better to tie that down with trust, so you both know what's going on on the ground as quickly as you can as well as to promote common interests and the feeling of being on the same page.
Overall, I see humiliation punishments as a failure. Mom is evoking the shame in the punishment in hopes that the child will associate this with whatever behaviour she's doing, but mom hasn't demonstrated why the behaviour shouldn't occur and in extension hasn't taken away her motivation for doing it in the first place (peer pressure, hypersexualization, having people think she's easy). Furthermore, in the off-chance that she has successfully associated twerking with punishment and will stfu and lay her head down like a good little girl, she will still have successfully associated unnecessary punishment with mom. And when you put your parent-child relationship at stake to get one point across, that's what I would call a very imprudent decision. She's missing the forest for a tree. Not the trees, one tree. A tactical decision should not compromise strategy - but perhaps there wasn't much of a coherent strategy to compromise in the first place.
And now I'm done judging her.