The timeline and BB's behaviour at the end isn't making sense to me

Judges summing up:
'Sharif went to work from 6.25pm. At 7.15pm there was a series of calls from Batool to Sharif, followed by incoming calls from Batool’s sisters to Batool.
Sharif accepted he was called home by Batool who said Sara was sick and stopped at Co Op on route. There is further phone evidence that shows 30 voice calls from Batool trying to reach her family.
Message at 8.38pm from one of the children to his friend, saying his sister passed away and a 42-minute phone call from Batool’s sister to Sharif.
US said he was called home by Batool who said Sara was sick. He went upstairs and hit Sara with a pole because he thought she was pretending. Batool did not think Sara was pretending to be unwell. Sharif told the jury that Sara passed away with one or two minutes after entering the room and he did not let Batool call an ambulance.
Sharif agreed that when he came home Sara was very ill but no one had called a doctor.'
The evidence is that US beat Sara the night before, this caused some kind of catastrophic injury that made her unwell. He went to work, Sara became gravely ill, BB makes lots of calls to her sisters and US. BB's sister makes a long call to US. US then goes home, sees the gravely ill child, hits her with a pole and she dies within a minute or two? There's two things I'm not sure about:
1. Why is BB frantically calling her sisters and why are her sisters calling US and having a 42 minute phone call when US is at work?
2. Why would an adult returning home from work because his child is ill walk straight up to the room, ascertain this dying child is 'faking it', grab a metal pole, hit her in the stomach and then a minute later realise she's dead?
Make it make sense?!
I think Sara had a very bad head injury from the night before from the beating by US, no doubt, but maybe BB has hit her in the stomach and that was the straw that broke the camels back in terms of systemic physiological failure in Sara's body? Why else would BB frantically phoned her sisters and then her sisters phone US? Sara was on deaths door, 2 minutes from death and her Dad chose to hit her in the stomach with an iron pole? It just doesn't fit IMO. That poor kid - I hope the truth of her death comes out. They owe it to her memory - evil twats.