Question: Why didn't Violet's mother stop the Oompa-Loompas from jumping on her daughter during their song? They didn't care about her comfort as they jumped on her from a big height, making the impact painful, and they also rolled her on her head, making her hit the floor and mopping it with her hair. She can be heard several times pleading with the Loompas to stop, crying for help and screaming. So why didn't her mother stop them?
Question: Are Violet and Mike stuck as being blue and stretched out permanently?
Answer: It's left vague in the film, but in the book, it's made clear that yes, they are stuck that way.
Answer: In the original movie with Gene Wilder, Wonka assures Charlie that "they will be returned to their nasty selves." In this version they are stuck like that forever as a lesson to other children.
Answer: It's unknown if they'll stay that way for the rest of their lives or if they'll eventually return to normal.
Answer: Yes.
Answer: I'll be completely honest - I think you may be drastically overthinking this quite a bit. There's nothing to suggest that the Oompa-Loompas are causing her significant pain, nor is screaming or crying as much as this question suggests. It's a highly stylized song sequence in a highly stylized movie. You shouldn't necessarily be watching it as though it were totally realistic and logical. But to give you something of an answer, you could also say the mum is just in a state of shock.
TedStixon