I know it's just a movie, but when Esther breaks her arm in the vise, wouldn't a doctor be able to tell it wasn't done by a human squeezing her arm?
Also, didn't John think it was suspicious that hours later, after Kate supposedly injured Esther's arm (I'm assuming it was supposed to be hours later), Esther is in excruciating pain?
I guess I really shouldn't be that surprised. John was so oblivious that he didn't notice anything!
In spite of this, I still felt bad when he was killed.
My daughters friend jumped off our trampoline once and hurt her ankle. She cried originally and I put ice on it but it looked fine and later on she was playing and running on it so we figured she was alright. Later on that night, hours later she was complaining about it again and this time it was swollen and looked bruised, her mom took her to the doctors first thing the next morning and found out it was broken. This happened on the first day of summer vacation, poor thing was in a cast all summer long. So it's possible to not feel it or know till later on.
It's not guaranteed that one type of break indicates abuse while another doesn't; it's not unusual in abuse cases to see a rotary-like break - where the arm or leg has been grabbed in a twisting pull and the bones have basically splintered at the break. If you imagine taking a small tree branch and twisting it until it breaks, that's not dissimilar to what would be seen in an ED in an abuse case. However, it's completely possible to have a rotary-like break accidentally, and a normal break from abuse. Not all that long ago, a jogger nearby managed, through amazing talent, to have a rotary-like break right above her ankle, and putting that back together was more complicated than a plain old break. Not a chance it was from abuse - her fall was seen by others, who phoned the EMTs. But in abuse cases where the abuse is known, the rotary-like break gives additional information about what happened, and it's uncommon for a child to be able to, say, break their own arm in a rotary break. It's not impossible, so it's not a 100% positive test for abuse, but that break combined with other factors can serve to confirm abuse.
Esther must be aware of this science of bone breaking because it is indeed very possible she's done this before, with one of the other families who have fallen victim to her. Before she puts her arm in the vice, she puts a screwdriver and rag in her mouth, for something to bite down on and to muffle her scream. (People forget: this isn't Esther's first time at the rodeo. She's killed a great number of people, and is obviously a master of mind games. She's had time to practice how to fake stuff. She's been doing it for 33 years.)
Well not 33 yrs lol. But how does that answer the OP's question? If anything, doing it before and knowing the difference between bone sizes should have made her more wary of doing it.