I wondered if the flight, was part of the scam.... after they had begged for money to get her to a specialist hospital in the USA, a private plane creates the illusion of poor Meg, unable to fly in a normal plane! And one they had started, they had to continue with the flight!
I did get a bit confused by the timeline, as the show goes all over the place. I think the scam for treatment in the USA, came after Meg had tried to do a runner and to go and stay with her friends when she was 19. So her mum when she called the police, and got Meg back, then had to get Meg away from her friends, so removed her to Disney land, for months. Then when they run out of money, they had to come home again!
The male friend was .....I thought, confused and not completely clear about what had been going on! I wondered how he had got back home to the UK after the flight, or did he end up in Disney land as well?
RE the scripts from Harrods, That was so dodgy, it looked as if Jean had managed to circumvent the system, by ordering the drugs directly, without a presecription, by pretending to be a pharmacy direct!
It must be confusing as a child or young adult to not believe the adults around you that you trust. If your mum is telling you you have a brain tumour, you must be likely to believe them, and take whatever drugs you are given. especially as Meg was home schooled and didnt seem to have a lot of family around her. If the police hadnt investigated Megs death, Jean could have got away with everything without a hint of suspicion about her activities